Biggest changeInterest and Other Income, Net The following table sets forth our interest and other income, net (dollars in thousands): Years Ended December 31, 2023 vs 2022 Change 2023 2022 $ % Interest and other income, net $ 9,172 $ 1,432 $ 7,740 541 % Interest and other income, net increased by $7.7 million in 2023 compared with 2022 mainly due to income from marketable securities corresponding to an increase in interest rates.
Biggest changeWe expect our general and administrative investments to be fairly constant in absolute dollars in the near term and potentially decline as a percentage of revenue over time in relation to anticipated longer-term increased revenue. 30 Table of Contents Interest Income and Other Expense, Net The following table sets forth our interest income and other expense, net (dollars in thousands): Years Ended December 31, 2024 vs 2023 Change 2024 2023 $ % Interest income and other expense, net $ 11,388 $ 9,172 $ 2,216 24 % Interest income and other expense, net increased by $2.2 million in 2024 compared with 2023 mainly due to a higher rate of interest earned on our cash, cash equivalents and marketable securities as well as a larger cash and marketable securities balance.
In addition, we periodically elect to ship by air versus by ocean in order to meet delivery commitments to our customers, which is more costly. Cost of revenue also includes fixed expenses related to our internal operations, which could increase our cost of revenue as a percentage of revenue if our revenue declines.
In addition, we periodically ship by air versus by ocean in order to meet delivery commitments to our customers, which is more costly. Cost of revenue also includes fixed expenses related to our internal operations, which could increase our cost of revenue as a percentage of revenue if our revenue declines.
Our income taxes may be subject to fluctuation during the year and in future years as new information is obtained, which may affect the assumptions used to estimate the annual effective tax rate, including factors such as actual results differing from our estimates of pre-tax earnings in the various jurisdictions in which we operate, which could impact the recognition of our deferred tax assets, the recognition or de-recognition of tax benefits related to uncertain tax positions and changes in or the interpretation of tax laws in jurisdictions where we conduct business. 2022 Compared to 2021 For a comparison of our results of operations for the years ended December 31, 2022 and 2021, see Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations” of our Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on February 21, 2023.
Our income taxes may be subject to fluctuation during the year and in future years as new information is obtained, which may affect the assumptions used to estimate the annual effective tax rate, including factors such as actual results differing from our estimates of pre-tax earnings in the various jurisdictions in which we operate, which could impact the recognition of our deferred tax assets, the recognition or de-recognition of tax benefits related to uncertain tax positions and changes in or the interpretation of tax laws in jurisdictions where we conduct business. 2023 Compared to 2022 For a comparison of our results of operations for the years ended December 31, 2023 and 2022, see Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations” of our Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on February 23, 2024.
Revenue fluctuations result from many factors, including, but not limited to: increases or decreases in customer orders for our products and services, market, financial or other factors that may delay or materially impact customer purchasing decisions, non-availability of products due to supply chain challenges, including component and labor shortages and increasing lead times as well as disruptions as a result of pandemics or natural disasters, contractual terms with customers that result in delayed revenue recognition and varying budget cycles and seasonal buying patterns of our customers.
Revenue fluctuations result from many factors, including, but not limited to: increases or decreases in customer orders for our products and services, market, financial or other factors such as government stimulus that may delay or materially impact customer purchasing decisions, non-availability of products due to supply chain challenges, including component and labor shortages and increasing lead times as well as disruptions as a result of pandemics or natural disasters, contractual terms with customers that result in delayed revenue recognition and varying budget cycles and seasonal buying patterns of our customers.
Revenue from sales of access and premises systems is recognized when control is transferred to the customer, which is generally when the products are shipped. Revenue from software platform licenses, which provides the customer with a right to use the software as it exists, is generally recognized upfront when product is made available to the customer.
Revenue from sales of access and premises systems is recognized when control is transferred to the customer, which is generally when the products are shipped. Revenue from software platform licenses, which provides the customer with a right to use the software as it exists, is generally recognized upfront when the license is made available to the customer.
Contractual Obligations and Commitments Our principal commitments as of December 31, 2023 consisted of our contractual obligations under non-cancelable outstanding purchase obligations and operating lease obligations for office space.
Contractual Obligations and Commitments Our principal commitments as of December 31, 2024 consisted of our contractual obligations under non-cancelable outstanding purchase obligations and operating lease obligations for office space.
Our customers range from smaller, regional service providers to some of the world’s largest service 27 Table of Contents providers. Customers are defined into small (less than 250,000 subscribers), medium (250,000 to 2.5 million subscribers) or large (greater than 2.5 million subscribers).
Our customers range from smaller, regional service providers to some of the world’s largest service providers. Customers are defined into small (less than 250,000 subscribers), medium (250,000 to 2.5 million subscribers) or large (greater than 2.5 million subscribers).
We base our estimates, assumptions and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances. To the extent there are material differences between these estimates and actual results, our financial statements may be affected. We evaluate our estimates, assumptions and judgments on an ongoing basis.
We base our estimates, assumptions and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances. To the extent there are material differences between these estimates and 27 Table of Contents actual results, our financial statements may be affected. We evaluate our estimates, assumptions and judgments on an ongoing basis.
Our revenue and potential revenue growth will depend on our ability to develop, market and sell our platform and managed services to strategically aligned customers of all types such as WISPs, fiber overbuilders, cable MSOs, municipalities and electric cooperatives in the United States and internationally.
Our revenue and potential revenue growth will depend on our ability to develop, market and sell our platform and managed services to strategically aligned customers of all types such as WISPs, fiber overbuilders, cable MSOs, municipalities and electric cooperatives in the U.S. and internationally.
Furthermore, we maintain a common stock repurchase program of which $113.6 million was available as of December 31, 2023. Our stock repurchase program does not require us to purchase a specific number of shares and may be modified, suspended or terminated at any time.
Furthermore, we maintain a common stock repurchase program of which $102.9 million was available as of December 31, 2024. Our stock repurchase program does not require us to purchase a specific number of shares and may be modified, suspended or terminated at any time.
As of December 31, 2023, our liability for taxes that would be payable because of repatriation of undistributed earnings of our foreign subsidiaries to the United States was not significant and limited to withholding taxes considering our existing net operating loss carryovers.
As of December 31, 2024, our liability for taxes that would be payable because of repatriation of undistributed earnings of our foreign subsidiaries to the U.S. was not significant and limited to withholding taxes considering our existing net operating loss carryovers.
The decrease in gross margin of 30 basis points, compared to the corresponding period in 2022, was mainly due to charges of $28.7 million recorded in the fourth quarter of 2023 as we wrote down obsolete inventory and accrued a liability for components at suppliers primarily associated with our legacy product family that existed before our shift to an all-platform model.
The increase in gross margin of 470 basis points, compared to the corresponding period in 2023, was primarily related to a charge of $28.7 million that we recorded in the fourth quarter of 2023 as we wrote down obsolete inventory and accrued a liability for components at suppliers primarily associated with our legacy product family that existed before our shift to an all-platform model.
As of December 31, 2023, we had cash, cash equivalents and marketable securities of $220.3 million, which consisted of deposits held at banks and major financial institutions and highly liquid marketable securities such as U.S. government securities and commercial paper. This includes $7.7 million of cash primarily held by our foreign subsidiaries.
As of December 31, 2024, we had cash, cash equivalents and marketable securities of $297.1 million, which consisted of deposits held at banks and major financial institutions and highly liquid marketable securities such as U.S. government securities and commercial paper. This includes $9.1 million of cash primarily held by our foreign subsidiaries.
This enables BSPs to grow their brand through increased subscriber acquisition, loyalty and revenue and to reduce their operating costs, creating value for their businesses and the communities they serve. We market our platform and managed services to communication service providers globally through our direct sales force as well as select resellers.
This enables BEPs to grow their businesses through increased 26 Table of Contents subscriber acquisition, loyalty and revenue and to reduce their operating costs, while creating value for their members, investors and the communities they serve. We market our platform and managed services to communication service providers globally through our direct sales force as well as select resellers.
See Note 5 “Commitments and Contingencies” of the Notes to Consolidated Financial Statements included in this Annual Report on Form 10-K for further discussion regarding our outstanding purchase commitments related to our third-party manufacturers. (2) Future minimum operating lease obligations in the table above primarily include payments for our office locations, which expire at various dates through 2029.
See Note 5 “Commitments and Contingencies” of the Notes to Consolidated Financial Statements included in this Annual Report on Form 10-K for further discussion regarding our outstanding purchase commitments related to our third-party manufacturers. 32 Table of Contents (2) Future minimum operating lease obligations in the table above primarily include payments for our office locations, which expire at various dates through 2033, including our new San Jose headquarters lease that will commence in August 2025.
Our contracts may include multiple performance obligations. For such arrangements, we allocate the contract’s transaction price to each performance obligation using the relative stand-alone selling price of each distinct good or service in the contract. We generally determine stand-alone selling prices based on the prices charged to customers or our best estimate of stand-alone selling price.
Our contracts generally include multiple performance obligations. For such arrangements, we allocate the contract’s transaction price to each performance obligation using the relative stand-alone selling price of each distinct good or service in the contract.
Our effective tax rate was lower than the federal statutory rate of 21% primarily due to research and development tax credits and provision to return adjustments, partially offset by the impact of stock-based compensation and uncertain tax positions. During 2022, our current tax expense was $11.1 million, and our deferred tax expense was $1.9 million.
Our effective tax rate was lower than the federal statutory rate of 21% primarily due to research and development tax credits and provision to return adjustments, partially offset by the impact of stock-based compensation and uncertain tax positions.
Financing Activities In 2023, net cash used in financing activities of $65.9 million consisted of purchases of our common stock of $86.4 million and payments related to a financing arrangement of $11.7 million, partially offset by proceeds from the issuance of common stock related to our equity plans of $32.1 million. 32 Table of Contents 2022 Compared to 2021 For a discussion of our liquidity and capital resources and our cash flow activities for the years ended December 31, 2022 and 2021, see Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” of our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on February 21, 2023.
Financing Activities In 2024, net cash provided by financing activities of $20.9 million consisted of the issuance of common stock related to our equity plans of $31.6 million partially offset by purchases of our common stock of $10.7 million. 2023 Compared to 2022 For a discussion of our liquidity and capital resources and our cash flow activities for the years ended December 31, 2023 and 2022, see Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” of our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 23, 2024.
Liquidity and Capital Resources Historically, we have funded our operations and investing activities primarily through cash flow generated from operations, sales of our common stock and various borrowing arrangements.
Liquidity and Capital Resources We fund our operations and investing activities primarily through cash flow generated from operations and sales of our common stock.
Non-cash charges consisted of stock-based compensation of $62.8 million, depreciation and amortization of $16.6 million and deferred income taxes of $0.7 million partially offset by net accretion of available-for-sale securities of $4.2 million.
Non-cash charges consisted of stock-based compensation of $70.8 million and depreciation and amortization of $19.6 million partially offset by deferred income taxes of $10.0 million and net accretion of available-for-sale securities of $5.3 million.
Income Taxes The following table sets forth our income taxes (dollars in thousands): Years Ended December 31, 2023 vs 2022 Change 2023 2022 $ % Income taxes $ 5,432 $ 13,032 $ (7,600) (58) % Effective tax rate 16 % 24 % During 2023, our current tax expense was $6.1 million, and our deferred tax expense was $(0.7) million.
Income Taxes The following table sets forth our income taxes (dollars in thousands): Years Ended December 31, 2024 vs 2023 Change 2024 2023 $ % Income taxes $ (1,899) $ 5,432 $ (7,331) (135) % Effective tax rate 6 % 16 % During 2024, our current tax expense was $8.1 million, and our deferred tax benefit was $10.0 million.
The increase in net cash provided by operating activities during 2023 as compared to 2022 was due primarily to an increase in our net operating results after adjustment of non-cash charges of $2.9 million and an increase in our net cash inflow resulting from changes in operating assets and liabilities of $26.1 million.
The increase in net cash provided by operating activities during 2024 as compared to 2023 was due primarily to an increase in our net cash inflow resulting from changes in operating assets and liabilities of $70.7 million partially offset by a decrease in our net operating results after adjustment of non-cash charges of $58.6 million.
Our primary focus has been, and in the near term will continue to be, the United States and Canada given our large, direct sales and marketing presence and the amount of government stimulus being invested into underserved and not-served areas of these countries. In 2022, we introduced our platform to the United Kingdom.
Revenue generated in the U.S. represented 92% of revenue in 2024 and 91% in 2023. Our primary focus has been, and in the near term will continue to be, the U.S. and Canada given our large, direct sales and marketing presence and the amount of government stimulus being invested into underserved and not-served areas of these countries.
The following table presents the cash inflows and outflows by activity during 2023 and 2022 (in thousands): Years Ended December 31, 2023 2022 Net cash provided by operating activities $ 56,251 $ 27,183 Net cash used in investing activities (6,245) (24,082) Net cash provided by financing activities (65,926) 25,063 Operating Activities Our operating activities provided cash of $56.3 million in 2023 and $27.2 million in 2022.
The following table presents the cash inflows and outflows by activity during 2024 and 2023 (in thousands): Years Ended December 31, 2024 2023 Net cash provided by operating activities $ 68,400 $ 56,251 Net cash used in investing activities (109,530) (6,245) Net cash provided by (used in) financing activities 20,897 (65,926) 31 Table of Contents Operating Activities Our operating activities provided cash of $68.4 million in 2024 and $56.3 million in 2023.
We believe the following critical accounting policies affect our significant judgments and estimates used in the preparation of our financial statements. 28 Table of Contents Revenue Recognition Revenue is recognized when a performance obligation is satisfied, which occurs when control of the promised goods or services is transferred to the customer, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services.
Revenue Recognition Revenue is recognized when a performance obligation is satisfied, which occurs when control of the promised goods or services is transferred to the customer, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services.
The following table sets forth our research and development expenses (dollars in thousands): Years Ended December 31, 2023 vs 2022 Change 2023 2022 $ % Research and development $ 177,772 $ 131,994 $ 45,778 35 % Percent of revenue 17 % 15 % Percent of gross profit 34 % 30 % The increase in research and development expenses of $45.8 million during 2023 compared with 2022 was mainly due to increases in personnel expenses of $31.7 million driven by increased headcount, stock-based compensation of $4.8 million, depreciation and amortization of $3.2 million, prototypes and test equipment expenses of $2.9 million and outside services of $1.2 million.
The following table sets forth our research and development expenses (dollars in thousands): Years Ended December 31, 2024 vs 2023 Change 2024 2023 $ % Research and development $ 179,870 $ 177,772 $ 2,098 1 % Percent of revenue 22 % 17 % Percent of gross profit 40 % 34 % The increase in research and development expenses of $2.1 million during 2024 compared with 2023 was mainly due to increases in depreciation and amortization of $3.0 million, stock-based compensation of $2.1 million, software subscriptions of $1.9 million and personnel expenses of $1.2 million.
The following table sets forth our sales and marketing expenses (dollars in thousands): Years Ended December 31, 2023 vs 2022 Change 2023 2022 $ % Sales and marketing $ 214,564 $ 174,549 $ 40,015 23 % Percent of revenue 21 % 20 % Sales and marketing expenses increased by $40.0 million during 2023 compared to 2022 primarily due to increases in personnel expenses of $29.4 million mainly related to increased sales headcount and higher sales incentive compensation corresponding to our increased revenue, stock-based compensation of $5.0 million and travel expenses of $2.2 million.
The following table sets forth our sales and marketing expenses (dollars in thousands): Years Ended December 31, 2024 vs 2023 Change 2024 2023 $ % Sales and marketing $ 217,879 $ 214,564 $ 3,315 2 % Percent of revenue 26 % 21 % Sales and marketing expenses increased by $3.3 million during 2024 compared to 2023 primarily due to increases in stock-based compensation of $3.9 million, marketing expenses of $0.8 million and travel expenses of $0.6 million.
Gross Profit and Gross Margin The following table sets forth our gross profit and gross margin (dollars in thousands): Years Ended December 31, 2023 vs 2022 Change 2023 2022 $ % Gross profit $ 518,316 $ 435,428 $ 82,888 19 % Gross margin 49.9 % 50.2 % Gross profit increased by $82.9 million to $518.3 million during 2023 from $435.4 million during 2022.
Gross Profit and Gross Margin The following table sets forth our gross profit and gross margin (dollars in thousands): Years Ended December 31, 2024 vs 2023 Change 2024 2023 $ % Gross profit $ 453,594 $ 518,316 $ (64,722) (12) % Gross margin 54.6 % 49.9 % Gross profit decreased by $64.7 million to $453.6 million during 2024 from $518.3 million during 2023.
We expect our investments in research and development to increase in absolute dollars as we seek to expand the functionality and capabilities of our platforms. General and Administrative Expenses General and administrative expenses consist primarily of personnel costs related to our executive, finance, human resources, information technology and legal organizations, outside consulting services, insurance, facilities and fees for professional services.
General and Administrative Expenses General and administrative expenses consist primarily of personnel costs related to our executive, finance, human resources, information technology and legal organizations, outside consulting services, insurance, facilities and fees for professional services. Professional services consist of outside audit, legal, accounting and tax services.
We expect our investments in sales and marketing will increase in absolute dollars as we extend our market reach and grow our business in support of our key strategic initiatives. 30 Table of Contents Research and Development Expenses Research and development expenses include personnel costs, outside contractor and consulting services, depreciation on lab equipment, costs of prototypes and overhead allocations.
We expect our investments in sales and marketing will be relatively flat in absolute dollars in the near term. Research and Development Expenses Research and development expenses include personnel costs, outside contractor and consulting services, depreciation on lab equipment, costs of prototypes and overhead allocations.
In addition, from time to time, we procure component inventory primarily as a result of manufacturing discontinuation of critical components by suppliers. Furthermore, post the global pandemic-induced supply chain challenges, we have purchased, and may continue to purchase, excess components from our suppliers and consigned back to our suppliers to be consumed on future finish good builds.
Furthermore, as a result of the global pandemic-induced supply chain challenges and supply assurance plans, we have purchased, and may continue to purchase, excess components from our suppliers and consign components back to our suppliers to be consumed on future finished good builds. We regularly monitor inventory on-hand and record write-downs for excess and obsolete inventory.
The following table sets forth our general and administrative expenses (dollars in thousands): Years Ended December 31, 2023 vs 2022 Change 2023 2022 $ % General and administrative $ 100,395 $ 76,275 $ 24,120 32 % Percent of revenue 10 % 9 % The increase in general and administrative expenses of $24.1 million in 2023 compared to 2022 was mainly due to increases in personnel expenses of $10.8 million driven by increased headcount, stock-based compensation of $8.0 million, litigation settlement of $3.2 million and outside services of $1.0 million.
The following table sets forth our general and administrative expenses (dollars in thousands): Years Ended December 31, 2024 vs 2023 Change 2024 2023 $ % General and administrative $ 98,879 $ 100,395 $ (1,516) (2) % Percent of revenue 12 % 10 % The decrease in general and administrative expenses of $1.5 million in 2024 compared to 2023 was mainly due to a decrease in legal costs due to a settlement in 2023 of $3.3 million and lower outside services expenses of $2.9 million.
Investing Activities In 2023, net cash used in investing activities of $6.2 million consisted of capital expenditures of $17.9 million, primarily consisting of purchases of test and computer equipment and software, partially offset by net maturities of marketable securities of $11.6 million.
Investing Activities In 2024, net cash used in investing activities of $109.5 million consisted of net purchases of marketable securities of $91.4 million and capital expenditures of $18.1 million, primarily consisting of purchases of test and computer equipment.
We regularly monitor inventory on-hand and record write-downs for excess and obsolete inventory based on our estimate of demand for our products, potential obsolescence of technology, product life cycles and whether pricing trends or forecasts indicate that the carrying value of inventory exceeds our estimated selling price.
These write-downs and accruals are based on our assumptions of demand for our products and requires significant judgement of relevant factors including a comparison of the quantity and cost of inventory on hand to our estimated forecast of customer demand, current levels of orders and backlog, market conditions, potential obsolescence of technology, product life cycles and whether pricing trends or forecasts indicate that the carrying value of inventory exceeds our estimated selling price.
Our effective tax rate was higher than the federal statutory rate of 21% due to state taxes, the U.S. tax impact of foreign operations, and the impact of stock-based compensation, partially offset by research and development tax credits and stock option windfall deductions. 31 Table of Contents We continue to maintain a valuation allowance of $29.9 million on certain U.S. federal and California state deferred tax assets that we believe are not more likely than not to be realized in future periods.
We continue to maintain a valuation allowance of $30.6 million on certain U.S. federal and California state deferred tax assets that we believe are not more likely than not to be realized in future periods.
Overview We develop, market and sell our platform (cloud, software and systems) and managed services that enable service providers of all types and sizes to innovate and transform their businesses.
Overview We develop, market and sell our appliance-based platform, cloud and managed services that enable service providers of all types and sizes to innovate and transform their businesses. For our customers to successfully transform their businesses into the innovative BEPs of the future, they require actionable data for critical business functions such as network operations, customer support and marketing.
The following table summarizes our contractual obligations as of December 31, 2023 (in thousands): Payments Due by Period Total Less Than 1 Year 1-3 Years 3-5 Years More Than 5 Years Non-cancelable purchase commitments (1) $ 219,989 $ 140,521 $ 69,145 $ 6,649 $ 3,674 Operating lease obligations (2) 12,454 4,676 5,978 1,576 224 $ 232,443 $ 145,197 $ 75,123 $ 8,225 $ 3,898 (1) Represents outstanding purchase commitments to be delivered by our third-party manufacturers or other vendors.
The following table summarizes our contractual obligations as of December 31, 2024 (in thousands): Payments Due by Period Total Less Than 1 Year 1-3 Years 3-5 Years More Than 5 Years Non-cancelable purchase commitments (1) $ 248,739 $ 129,607 $ 81,709 $ 35,951 $ 1,472 Operating lease obligations (2) 17,374 4,528 5,152 3,544 4,150 $ 266,113 $ 134,135 $ 86,861 $ 39,495 $ 5,622 (1) Represents outstanding purchase commitments to be delivered by our third-party manufacturers or other vendors.
These factors are impacted by market and economic conditions, competitive dynamics, technology changes and new product introductions and require estimates that may include elements that are uncertain. Actual demand may differ from forecasted demand and may have a material effect on gross profit.
Factors that could influence management’s assumptions and judgements include changes in economic conditions, competitive dynamics, losing a key customer, changes in our customers’ capital expenditures, government investment programs, technology changes, new product introductions and supply-chain lead times. Actual demand may differ from forecasted demand and may have a material effect on gross profit.
Our platform, which includes Calix Cloud, Revenue EDGE and Intelligent Access EDGE, gathers, analyzes and applies machine learning to deliver real-time insights seamlessly to each key business function. Our customers utilize these insights to simplify network operations, marketing and customer support and deliver a growing portfolio of SmartLife managed services and experiences that excite their subscribers.
Our customers utilize these insights to simplify network operations, marketing and customer support and innovate for their customers, business and municipal subscribers by delivering a growing portfolio of SmartLife™ managed services and experiences.
Results of Operations for Years Ended December 31, 2023 and 2022 Revenue The following table sets forth our revenue (dollars in thousands): Years Ended December 31, 2023 vs 2022 Change 2023 2022 $ % Revenue $ 1,039,593 $ 867,827 $ 171,766 20 % 29 Table of Contents Our revenue increased by $171.8 million, or 20%, during 2023 compared with 2022.
Results of Operations for Years Ended December 31, 2024 and 2023 Revenue The following table sets forth our revenue by customer size (dollars in thousands): Years Ended December 31, 2024 vs 2023 Change 2024 2023 $ % Large $ 50,776 $ 82,627 $ (31,851) (39) % Medium 123,977 166,820 (42,843) (26) % Small 656,765 790,146 (133,381) (17) % $ 831,518 $ 1,039,593 $ (208,075) (20) % Our revenue decreased by $208.1 million, or 20%, during 2024 compared with 2023.
These changes were partially offset by an increase in accrued liabilities of $32.7 million, mainly due to an increase in the reserves for inventory at suppliers, a decrease in inventory of $16.2 million and an increase in deferred revenue of $2.9 million.
These changes were partially offset by a decrease in accrued liabilities of $36.0 million, a decrease in accounts payable of $15.1 million due to the lower inventory purchases and a decrease in deferred revenue of $13.9 million due to a change in billing practices towards monthly versus annual.
In 2023, cash outflows from changes in operating assets and liabilities primarily consisted of an increase in prepaid expenses and other assets of $60.8 million, mainly due to advanced payments to supply chain partners, an increase in prepaid taxes and reclassification of contract assets from deferred revenue; an increase in accounts receivable of $32.2 million due to the timing of shipments; and a decrease in accounts payable of $6.4 million due to the timing of inventory payments.
In 2024, cash inflows from changes in operating assets and liabilities primarily consisted of decreases in accounts receivable of $46.7 million and inventory of $30.3 million, both due to lower revenue, and a decrease in prepaid expenses and other assets of $11.2 million.
Operating Expenses Sales and Marketing Expenses Sales and marketing expenses consist of personnel costs, employee sales commissions, marketing programs and events, software tools and travel-related expenses.
Additionally, we continued to experience growth in our licenses, cloud and managed services, which became a greater percentage of our total revenue since the overall decline in revenue was related to our appliance revenue. 29 Table of Contents Operating Expenses Sales and Marketing Expenses Sales and marketing expenses consist of personnel costs, employee sales commissions, marketing programs and events, software tools and travel-related expenses.
If inventory is written down, a new cost basis is established that cannot be increased in future periods. The sale of previously reserved inventory has not had a material impact on our gross margin. Recent Accounting Pronouncements Not Yet Adopted There have been no additional accounting pronouncements or changes in accounting pronouncements that are significant or potentially significant to us.
If inventory is written down, a new cost basis is established that cannot be increased in future periods.