in 2020 , 2019 , and 2018 , 33.8 % , 32.3 % , and 28.7 % , respectively , of our total revenue was generated from customers outside of the united states . as of december 31 , 2020 , we operated in 12 countries . we believe we have a significant opportunity to grow our international footprint . we are investing in new geographies , including through investment in direct and indirect sales channels , professional services , and customer support and implementation partners . we have experienced strong revenue growth , with revenue of $ 304.6 million , $ 260.4 million , and $ 226.7 million in 2020 , 2019 , and 2018 , respectively . our subscriptions revenue was $ 198.7 million , $ 151.3 million , and $ 126.0 million in 2020 , 2019 , 45 and 2018 , respectively , and includes sales of our saas subscriptions , on-premises term license subscriptions , and maintenance support . our cloud subscription revenue was $ 129.2 million , $ 95.0 million , and $ 67.4 million in 2020 , 2019 , and 2018 , respectively . we have invested in developing our platform , expanding our sales and marketing and research and development capabilities , and providing general and administrative resources to support our growth . we intend to continue to invest in our business to take advantage of our market opportunity . as a result , we incurred net losses of $ 33.5 million , $ 50.7 million , and $ 49.5 million in 2020 , 2019 , and 2018 , respectively . we also used cash in operations of $ 7.6 million , $ 8.9 million , and $ 31.3 million in 2020 , 2019 , and 2018 , respectively . covid-19 beginning in late 2019 and continuing into 2021 , the outbreak of the novel coronavirus disease , or covid-19 , has resulted in the declaration of a global pandemic and adversely affected economic activity across virtually all sectors and industries on a local , national , and global scale . the impact of covid-19 on the economy and our business continues to be a fluid situation . operationally , we remain focused on supporting our customers , employees , and communities during this time . we have responded quickly to adopt a virtual corporate strategy consisting of enabling most of our employees to work productively from home while continuing to guard the health and safety of our teams , support our customers , and mitigate risk . we are focused on ensuring continuity for our customers . to the extent possible , we are conducting business as usual , with necessary or advisable modifications to employee travel , employee work locations , and marketing events . through december 31 , 2020 , we have not seen a meaningful adverse impact to our financial position , results of operations , and cash flows and liquidity as a result of covid-19 . while the verticals from which we have historically generated the majority of our revenue have been less impacted by covid-19 to date , there may be impacts to our financial condition and results of operations in 2021 as a result of reduced demand for our products and services and longer sales cycles . the ultimate impact of covid-19 on our business is not estimable at this time and will be largely dependent upon a number of factors outside of our control including the extent and duration of the outbreak as well as any mitigating actions which may be undertaken by global governments and the general public . our business model our business model focuses on maximizing the lifetime value of customer relationships , which is a function of the duration of a customer 's deployment of appian as well as the price and number of subscriptions of appian a customer purchases . we incur significant customer acquisition costs , including expenses associated with hiring new sales representatives , who generally take more than one year to become productive given the length of our sales cycle , and marketing costs , all of which , with the exception of sales commissions , are expensed as incurred . at the same time , we believe the costs we incur to retain customers and drive additional purchases of software are lower than our customer acquisition costs on a relative basis . over time , we expect a large portion of our customers to renew their subscriptions and purchase additional subscriptions as they continue to build more applications and add more users to our platform . over the last three completed fiscal years , we had an average cloud subscription renewal rate of 98 % . we calculate our cloud subscription renewal rate by dividing ( i ) the cloud subscription revenue from renewing cloud customers in the current 12-month period that were cloud customers during the entirety of the prior 12-month period , giving effect to price increases but excluding additional cloud subscriptions for additional users , or upsells , by ( ii ) our cloud subscription revenue from all cloud customers in the corresponding prior 12-month period that were cloud customers during the entirety of such prior 12-month period . for example , to obtain our cloud subscription renewal rate for the 12-month period ended december 31 , 2020 , we identified the amount of cloud subscription revenue in 2020 from cloud customers that were our cloud customers for all of 2019 and subtracted the amount of upsells to such cloud customers and new users from those cloud customers in 2020. we then divided the balance of 2020 cloud subscription revenue from such cloud customers by all cloud subscription revenue generated in 2019 from cloud customers that were cloud customers for the entirety of 2019. with respect to the average for our last three completed fiscal years , we calculated the average of the three applicable 12-month periods . story_separator_special_tag professional services 51 our professional services revenue is comprised of fees for consulting services , including application development , deployment assistance , and training related to our platform . over time , as the need for professional services associated with user deployments decreases and the number of end users increases , we expect professional services revenue as a percentage of total revenue to decrease . additionally , if there is a decline in our procurement of new customers as a result of the covid-19 pandemic , we may also see a similar decline in professional services revenue . we have several strategic partnerships , including with kpmg , pwc , accenture , and deloitte . our agreements with our strategic partners have indefinite terms and may be terminated for convenience by either party . we intend to further grow our base of strategic partners to provide broader customer coverage and solution delivery capabilities . these partners refer software subscription customers to us and generally perform professional services with respect to any new service contracts they originate , increasing our subscriptions revenue without any change to our professional services revenue . as we expand the network of strategic partners , we expect professional services revenue to decline as a percentage of total revenue over time since our strategic partners may perform professional services associated with software subscriptions we sell . cost of revenue subscriptions cost of subscriptions revenue consists primarily of fees paid to our third-party managed hosting providers and other third-party service providers , personnel costs , including payroll and benefits for our technology operations and customer support teams , and allocated facility costs and overhead . we expect cost of revenue to continue to increase in absolute dollars for the foreseeable future as our customer base grows . professional services cost of professional services revenue includes all direct and indirect costs to deliver our professional services and training , including employee compensation for our global professional services and training personnel , third-party contractor costs , allocated facility costs and overhead , and the costs of billable expenses such as travel and lodging . the unpredictability of the timing of entering into significant professional services agreements sold on a standalone basis may cause significant fluctuations in our quarterly financial results and allocated facility costs and overhead . gross margin gross profit and gross margin , or gross profit as a percentage of total revenue , have been , and will continue to be , affected by various factors , including the mix of saas subscriptions and on-premises term license subscriptions , the mix of total subscriptions revenue and professional services revenue , subscription pricing , the costs associated with third-party hosting facilities , and the extent to which we expand our professional services to support future growth . our gross margin may fluctuate from period to period based on the above factors . subscriptions gross margin subscriptions gross margin is primarily affected by the growth in our subscriptions revenue as compared to the growth in , and timing of , costs to support such revenue . we expect to continue to invest in customer support and saas operations to support growth in our business , and the timing of those investments is expected to cause gross margins to fluctuate in the short term but improve over time . professional services gross margin professional services gross margin is affected by the growth in our professional services revenue as compared to the growth in , and timing of , the cost of our customer success organization as we continue to invest in the growth of our business . professional services gross margin is also impacted by the amount of services performed by subcontractors and partners as opposed to internal resources . more recently , we have reduced our usage of subcontractors , and the covid-19 pandemic has resulted in fewer in-person professional services engagements and deployments , both of which have reduced certain classes of expenses and improved professional services margins . however , our improved margins may not be indicative of future trends 52 and are subject to fluctuation based on factors discussed above and uncertainties related to the covid-19 pandemic outside of our control . operating expenses operating expenses consist of sales and marketing , research and development , and general and administrative expenses . salaries , bonuses , and other personnel-related costs are the most significant components of each of these expense categories . in general , our operating expenses are expected to continue to increase as we invest resources in growing our various teams . we grew from 1,275 employees at december 31 , 2019 to 1,460 employees at december 31 , 2020 , and we expect to continue to hire new employees in order to support our anticipated revenue growth . sales and marketing expense sales and marketing expense primarily includes personnel costs , including salaries , bonuses , commissions , stock-based compensation , and other personnel costs related to sales teams . additional expenses in this category include travel and entertainment , marketing activities and promotional events , subcontracting fees , and allocated facility costs and overhead . the number of employees in sales and marketing functions grew from 403 at december 31 , 2019 to 445 at december 31 , 2020. in order to continue to grow our business , geographical footprint , and brand awareness , we expect to continue investing resources in sales and marketing by increasing the number of sales and account management teams . as a result , we expect sales and marketing expense to increase in absolute dollars as we continue to invest to acquire new customers and further expand usage of our platform within our existing customer base . research and development expense research and development expense consists primarily of personnel costs for our employees who develop and enhance our platform , including salaries , bonuses , stock-based compensation , and other personnel costs . also included are non-personnel

liquidity and capital resources the following table presents selected financial information and statistics as of and for the years ended december 31 , 2020 , 2019 , and 2018 ( in thousands ) : replace_table_token_19_th as of december 31 , 2020 , we ha d $ 112.5 million of cash and cash equivalents and $ 109.8 million of short-term investments and marketable securities . we believe our existing cash and cash equivalents and short-term investments and marketable securities , together with any positive cash flows from operations and available borrowings under our revolving line of credit , will be sufficient to support working capital and capital expenditure requirements for at least the next 12 months . our future capital requirements will depend on many factors , including our growth rate , the timing and extent of spending to support research and development efforts , the expansion of sales and marketing activities , particularly internationally , the introduction of new and enhanced products and functions as well as platform enhancements and professional services offerings , the level of market acceptance of our applications , spending we may incur on our new headquarters , and the global economic uncertainty caused by the covid-19 pandemic and its impact on financial market conditions and our business . in the event additional financing is required from outside sources , we may be unable to raise the funds on acceptable terms , if at all . to the extent existing cash and cash equivalents , short-term investments , and cash from operations are not sufficient to fund future activities , we may need to raise additional funds . we may seek to raise additional funds through equity , equity-linked , or debt financings . if we raise additional funds through the incurrence of indebtedness , such indebtedness may have rights that are senior to holders of our equity securities and could contain covenants that restrict operations . any additional equity financing may be dilutive to our existing stockholders .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```liquidity and capital resources the following table presents selected financial information and statistics as of and for the years ended december 31 , 2020 , 2019 , and 2018 ( in thousands ) : replace_table_token_19_th as of december 31 , 2020 , we ha d $ 112.5 million of cash and cash equivalents and $ 109.8 million of short-term investments and marketable securities . we believe our existing cash and cash equivalents and short-term investments and marketable securities , together with any positive cash flows from operations and available borrowings under our revolving line of credit , will be sufficient to support working capital and capital expenditure requirements for at least the next 12 months . our future capital requirements will depend on many factors , including our growth rate , the timing and extent of spending to support research and development efforts , the expansion of sales and marketing activities , particularly internationally , the introduction of new and enhanced products and functions as well as platform enhancements and professional services offerings , the level of market acceptance of our applications , spending we may incur on our new headquarters , and the global economic uncertainty caused by the covid-19 pandemic and its impact on financial market conditions and our business . in the event additional financing is required from outside sources , we may be unable to raise the funds on acceptable terms , if at all . to the extent existing cash and cash equivalents , short-term investments , and cash from operations are not sufficient to fund future activities , we may need to raise additional funds . we may seek to raise additional funds through equity , equity-linked , or debt financings . if we raise additional funds through the incurrence of indebtedness , such indebtedness may have rights that are senior to holders of our equity securities and could contain covenants that restrict operations . any additional equity financing may be dilutive to our existing stockholders .
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 Suspicious Activity Report : in 2020 , 2019 , and 2018 , 33.8 % , 32.3 % , and 28.7 % , respectively , of our total revenue was generated from customers outside of the united states . as of december 31 , 2020 , we operated in 12 countries . we believe we have a significant opportunity to grow our international footprint . we are investing in new geographies , including through investment in direct and indirect sales channels , professional services , and customer support and implementation partners . we have experienced strong revenue growth , with revenue of $ 304.6 million , $ 260.4 million , and $ 226.7 million in 2020 , 2019 , and 2018 , respectively . our subscriptions revenue was $ 198.7 million , $ 151.3 million , and $ 126.0 million in 2020 , 2019 , 45 and 2018 , respectively , and includes sales of our saas subscriptions , on-premises term license subscriptions , and maintenance support . our cloud subscription revenue was $ 129.2 million , $ 95.0 million , and $ 67.4 million in 2020 , 2019 , and 2018 , respectively . we have invested in developing our platform , expanding our sales and marketing and research and development capabilities , and providing general and administrative resources to support our growth . we intend to continue to invest in our business to take advantage of our market opportunity . as a result , we incurred net losses of $ 33.5 million , $ 50.7 million , and $ 49.5 million in 2020 , 2019 , and 2018 , respectively . we also used cash in operations of $ 7.6 million , $ 8.9 million , and $ 31.3 million in 2020 , 2019 , and 2018 , respectively . covid-19 beginning in late 2019 and continuing into 2021 , the outbreak of the novel coronavirus disease , or covid-19 , has resulted in the declaration of a global pandemic and adversely affected economic activity across virtually all sectors and industries on a local , national , and global scale . the impact of covid-19 on the economy and our business continues to be a fluid situation . operationally , we remain focused on supporting our customers , employees , and communities during this time . we have responded quickly to adopt a virtual corporate strategy consisting of enabling most of our employees to work productively from home while continuing to guard the health and safety of our teams , support our customers , and mitigate risk . we are focused on ensuring continuity for our customers . to the extent possible , we are conducting business as usual , with necessary or advisable modifications to employee travel , employee work locations , and marketing events . through december 31 , 2020 , we have not seen a meaningful adverse impact to our financial position , results of operations , and cash flows and liquidity as a result of covid-19 . while the verticals from which we have historically generated the majority of our revenue have been less impacted by covid-19 to date , there may be impacts to our financial condition and results of operations in 2021 as a result of reduced demand for our products and services and longer sales cycles . the ultimate impact of covid-19 on our business is not estimable at this time and will be largely dependent upon a number of factors outside of our control including the extent and duration of the outbreak as well as any mitigating actions which may be undertaken by global governments and the general public . our business model our business model focuses on maximizing the lifetime value of customer relationships , which is a function of the duration of a customer 's deployment of appian as well as the price and number of subscriptions of appian a customer purchases . we incur significant customer acquisition costs , including expenses associated with hiring new sales representatives , who generally take more than one year to become productive given the length of our sales cycle , and marketing costs , all of which , with the exception of sales commissions , are expensed as incurred . at the same time , we believe the costs we incur to retain customers and drive additional purchases of software are lower than our customer acquisition costs on a relative basis . over time , we expect a large portion of our customers to renew their subscriptions and purchase additional subscriptions as they continue to build more applications and add more users to our platform . over the last three completed fiscal years , we had an average cloud subscription renewal rate of 98 % . we calculate our cloud subscription renewal rate by dividing ( i ) the cloud subscription revenue from renewing cloud customers in the current 12-month period that were cloud customers during the entirety of the prior 12-month period , giving effect to price increases but excluding additional cloud subscriptions for additional users , or upsells , by ( ii ) our cloud subscription revenue from all cloud customers in the corresponding prior 12-month period that were cloud customers during the entirety of such prior 12-month period . for example , to obtain our cloud subscription renewal rate for the 12-month period ended december 31 , 2020 , we identified the amount of cloud subscription revenue in 2020 from cloud customers that were our cloud customers for all of 2019 and subtracted the amount of upsells to such cloud customers and new users from those cloud customers in 2020. we then divided the balance of 2020 cloud subscription revenue from such cloud customers by all cloud subscription revenue generated in 2019 from cloud customers that were cloud customers for the entirety of 2019. with respect to the average for our last three completed fiscal years , we calculated the average of the three applicable 12-month periods . story_separator_special_tag professional services 51 our professional services revenue is comprised of fees for consulting services , including application development , deployment assistance , and training related to our platform . over time , as the need for professional services associated with user deployments decreases and the number of end users increases , we expect professional services revenue as a percentage of total revenue to decrease . additionally , if there is a decline in our procurement of new customers as a result of the covid-19 pandemic , we may also see a similar decline in professional services revenue . we have several strategic partnerships , including with kpmg , pwc , accenture , and deloitte . our agreements with our strategic partners have indefinite terms and may be terminated for convenience by either party . we intend to further grow our base of strategic partners to provide broader customer coverage and solution delivery capabilities . these partners refer software subscription customers to us and generally perform professional services with respect to any new service contracts they originate , increasing our subscriptions revenue without any change to our professional services revenue . as we expand the network of strategic partners , we expect professional services revenue to decline as a percentage of total revenue over time since our strategic partners may perform professional services associated with software subscriptions we sell . cost of revenue subscriptions cost of subscriptions revenue consists primarily of fees paid to our third-party managed hosting providers and other third-party service providers , personnel costs , including payroll and benefits for our technology operations and customer support teams , and allocated facility costs and overhead . we expect cost of revenue to continue to increase in absolute dollars for the foreseeable future as our customer base grows . professional services cost of professional services revenue includes all direct and indirect costs to deliver our professional services and training , including employee compensation for our global professional services and training personnel , third-party contractor costs , allocated facility costs and overhead , and the costs of billable expenses such as travel and lodging . the unpredictability of the timing of entering into significant professional services agreements sold on a standalone basis may cause significant fluctuations in our quarterly financial results and allocated facility costs and overhead . gross margin gross profit and gross margin , or gross profit as a percentage of total revenue , have been , and will continue to be , affected by various factors , including the mix of saas subscriptions and on-premises term license subscriptions , the mix of total subscriptions revenue and professional services revenue , subscription pricing , the costs associated with third-party hosting facilities , and the extent to which we expand our professional services to support future growth . our gross margin may fluctuate from period to period based on the above factors . subscriptions gross margin subscriptions gross margin is primarily affected by the growth in our subscriptions revenue as compared to the growth in , and timing of , costs to support such revenue . we expect to continue to invest in customer support and saas operations to support growth in our business , and the timing of those investments is expected to cause gross margins to fluctuate in the short term but improve over time . professional services gross margin professional services gross margin is affected by the growth in our professional services revenue as compared to the growth in , and timing of , the cost of our customer success organization as we continue to invest in the growth of our business . professional services gross margin is also impacted by the amount of services performed by subcontractors and partners as opposed to internal resources . more recently , we have reduced our usage of subcontractors , and the covid-19 pandemic has resulted in fewer in-person professional services engagements and deployments , both of which have reduced certain classes of expenses and improved professional services margins . however , our improved margins may not be indicative of future trends 52 and are subject to fluctuation based on factors discussed above and uncertainties related to the covid-19 pandemic outside of our control . operating expenses operating expenses consist of sales and marketing , research and development , and general and administrative expenses . salaries , bonuses , and other personnel-related costs are the most significant components of each of these expense categories . in general , our operating expenses are expected to continue to increase as we invest resources in growing our various teams . we grew from 1,275 employees at december 31 , 2019 to 1,460 employees at december 31 , 2020 , and we expect to continue to hire new employees in order to support our anticipated revenue growth . sales and marketing expense sales and marketing expense primarily includes personnel costs , including salaries , bonuses , commissions , stock-based compensation , and other personnel costs related to sales teams . additional expenses in this category include travel and entertainment , marketing activities and promotional events , subcontracting fees , and allocated facility costs and overhead . the number of employees in sales and marketing functions grew from 403 at december 31 , 2019 to 445 at december 31 , 2020. in order to continue to grow our business , geographical footprint , and brand awareness , we expect to continue investing resources in sales and marketing by increasing the number of sales and account management teams . as a result , we expect sales and marketing expense to increase in absolute dollars as we continue to invest to acquire new customers and further expand usage of our platform within our existing customer base . research and development expense research and development expense consists primarily of personnel costs for our employees who develop and enhance our platform , including salaries , bonuses , stock-based compensation , and other personnel costs . also included are non-personnel

