our platform and its associated solutions are sold to customers on a subscription basis and can be deployed through our unique cloud-based architecture that leverages both our global data centers as well as optional points-of-presence behind our customers ' firewalls . our flexible deployment model enables us to deliver superior security and compliance while maintaining the favorable economics afforded by cloud computing , creating a competitive advantage for us over legacy on-premises and cloud-only offerings . 35 we were founded in 2002 to provide a unified solution to help enterprises address their growing data security requirements . our first solution was commercially released in 2003 to combat the burgeoning problem of spam and viruses and their impact on corporate email systems . to address the evolving threat landscape and the adoption of communication and collaboration systems beyond corporate email and networks , we have broadened our solutions to defend against a wide range of threats , including email , mobile apps and social media , to protect the information people create from both compromise and compliance risks , and to archive and govern corporate information . today , our solutions are used worldwide to protect well over 100 million end users at enterprise customers , and millions more via service providers through our cloudmark division . as the threat environment has continued to evolve , we have dedicated significant resources to meet the ongoing challenges that this highly dynamic environment creates for our customers such as investing significantly to expand the breadth of our data protection platform as these expenditures are primarily in connection with the replacement and upgrade of equipment to lower the cost of deployment as well as to improve the efficiency for our cloud-based architecture . our business is based on a recurring revenue model . our customers pay a subscription fee to license the various components of our saas platform for a contract term that is typically one to three years . at the end of the license term , customers may renew their subscription and in each year since the launch of our first solution in 2003 , we have maintained a renewal rate with our existing customers of over 90 % . we derive this retention rate by calculating the total annually recurring subscription revenue from customers currently using our saas platform and dividing it by the total annually recurring subscription revenue from both these current customers as well as all business lost through non-renewal . we market and sell our solutions worldwide both directly through our sales teams and indirectly through a hybrid model where our sales organization actively assists our network of distributors and resellers . we also derive a lesser portion of our total revenue from the license of our solutions to strategic partners who offer our solutions in conjunction with one or more of their own products or services . our solutions are designed to be implemented , configured and operated without the need for any training or professional services . we offer various training and professional services for those customers that seek to develop deeper expertise in the use of our solutions or would like assistance with complex configurations or the importing of data . in some cases , we provide a hardware appliance to those customers that elect to host elements of our solution behind their firewall . increasing adoption of virtualization in the data center has led to a decline in the sales of our hardware appliances and a shift towards our software-based virtual appliances , which are delivered as a download via the internet . our hardware and services offerings carry lower margins and are provided as a courtesy to our customers . we expect the overall proportion of revenue derived from the hardware and services offerings to generally remain below 5 % of our total revenue . historically , the majority of our revenue was derived from our customers in the united states . we believe the markets outside of the united states offer an opportunity for growth and we intend to make additional investments in sales and marketing to expand in these markets . revenue from customers outside of the united states grew 32 % for the year ended december 31 , 2019 as compared to the prior year . in terms of customer concentration , there were two partners who accounted for 12 % and 11 % , respectively , of our total revenue in 2019. in 2018 and 2017 , one partner accounted for 12 % of our total revenue in each year . these partners sold to a number of end users , none of which accounted for more than 10 % of our total revenue in 2019 , 2018 and 2017. we have not been profitable to date and will need to grow revenue at a rate faster than our investments in cost of revenue and operating expenses in order to achieve profitability , as discussed in more detail below . key opportunities and challenges the total costs associated with the teams tasked with closing business with new customers and additional business with our existing customers have represented more than 90 % of our total sales and marketing costs since 2008. although we expect customers to be profitable over the duration of the customer relationship , the upfront costs typically exceed related revenue during the earlier periods of a contract . as a result , while our practice of invoicing our customers for the entire amount of the contract at the start of the term provides us with a relatively immediate contribution to cash flow , the revenue is recognized ratably over the term of the contract , and hence contributions toward operating income are limited in the period where the sales and marketing costs are incurred . accordingly , an increase in the mix of new customers as a percentage of total customers would likely negatively impact our near-term operating results . story_separator_special_tag for the software developed for use on our customers ' premises , the costs associated with the development work between technological feasibility and the general availability has not been material and as such we have not capitalized any of these development costs to date . sales and marketing . sales and marketing expenses include personnel costs , sales commissions , and other costs including travel and entertainment , marketing and promotional events , public relations and marketing activities . these costs also include amortization of intangible assets as a result of our past acquisitions . due to our continued investment in growing our sales and marketing operations , both domestically and internationally , headcount increases were reflected in higher compensation expense consistent with our revenue growth . our sales personnel are typically not immediately productive , and therefore the increase in sales and marketing expenses we incur when we add new sales representatives is not immediately offset by increased revenue and may not result in increased revenue over the long-term if these new sales people fail to become productive . the timing of our hiring of new sales personnel and the rate at which they generate incremental revenue will affect our future financial performance . we expect that sales and marketing expenses will continue to increase in absolute dollars and be among the most significant components of our operating expenses . general and administrative . general and administrative expenses consist of personnel costs , consulting services , audit fees , tax services , legal expenses and other general corporate items . as a result of our operational growth , we expect our general and administrative expenses to increase in absolute dollars in future periods as we continue to expand our operations and hire additional personnel . interest expense interest expense consists of interest expense and loss on conversion related to our convertible senior notes . other income , net other income , net , consists primarily of interest income earned on our cash , cash equivalents and short-term investments , and the net effect of foreign currency transaction gains and losses . ( provision for ) benefit from income taxes for most of the prior years , our income tax expense or benefit were primarily related to state and foreign income taxes . as we have incurred operating losses in all periods to date and recorded a full valuation allowance against our deferred tax assets , we had not historically recorded a provision for federal income taxes . however , in the year ended december 31 , 2017 , we recognized $ 0.2 million of deferred tax benefit in the u.s. related to amortization of tax goodwill on business acquisitions and $ 12.3 million of deferred tax benefit in the u.s. related to changes in the company 's valuation allowance resulting from the cloudmark , inc. and weblife balance , inc. business acquisitions . for the year ended december 31 , 2018 , we recognized $ 14.7 million of deferred tax benefit in the u.s. related to changes in the company 's valuation allowance resulting from the wombat security technologies , inc. acquisition . for the year ended december 31 , 2019 , we recognized $ 0.3 million of deferred tax benefit in the u.s. related to amortization of tax goodwill on certain business acquisitions . realization of any of our deferred tax assets depends upon future earnings , the timing and amount of which are uncertain . utilization of our net operating losses and research and development credits may be subject to substantial annual limitation due to the ownership change limitations provided by the internal revenue code and similar state provisions . analyses have been conducted to determine whether an ownership change had occurred since inception . the analyses have indicated that although ownership changes have occurred in prior years , the net operating losses and research and development credits would not expire before utilization as a result of the ownership change . in the event we have subsequent changes in ownership , net operating losses and research and development credit carryovers could be limited and may expire unutilized as a result of the subsequent ownership change . 41 results of operations the following table is a summary of our consolidated statements of operations . replace_table_token_9_th the following table sets forth our consolidated results of operations for the specified periods as a percentage of our total revenue for those periods . replace_table_token_10_th ( 1 ) includes stock-based compensation and amortization of intangible assets as follows : 42 replace_table_token_11_th revenue replace_table_token_12_th subscription revenue increased $ 170.6 million and $ 198.0 million , or 24 % and 39 % , respectively , for 2019 and 2018. these increases were due to a $ 128.6 million and $ 153.1 million increase in revenue from the united states and a $ 42.0 million and $ 44.9 million increase from international customers for 2019 and 2018 , respectively . the increases in subscription revenue for 2019 and 2018 were due to the ongoing demand for our solutions , increase in add-on activity and renewal rate being higher than 90 % . our enterprise customer count , which consists of customers that generate more than $ 10,000 in annual recurring revenue , increased from approximately 6,100 at the end of 2018 to approximately 7,100 , or 16 % , at the end of 2019. in addition , the number of customers with three or more products increased 38 % in 2019 as compared to 2018. our enterprise customer count increased from approximately 4,400 at the end of 2017 to approximately 6,100 , or 39 % , at the end of 2018. the revenue recognized from acquired deferred revenue related to the acquisitions we made was $ 5.8 million , $ 20.8 million and $ 3.2 million in 2019 , 2018 and 2017 , respectively . the change in subscription revenue due to pricing was not significant for either period . hardware and services revenue for

cash flows the following table sets forth a summary of our consolidated cash flows for the periods indicated : replace_table_token_23_th net cash flows provided by operating activities our net loss and cash flows from operating activities are significantly influenced by our investments in headcount and data center operations to support anticipated growth . our cash flows are also influenced by cash payments from customers . we invoice customers for the entire contract amount at the start of the term , and as such our cash flow from operations is also affected by the length of a customer contract . net cash provided by operating activities was $ 242.5 million in 2019 as compared to $ 184.7 million in 2018. the increase of $ 57.8 million was primarily due to : an increase in amortization of intangible assets of $ 4.5 million due to acquired businesses , and an increase in depreciation of fixed assets of $ 2.3 million due to an increase in capital expenditures ; an increase in stock-based compensation expense of $ 33.6 million due to the increase in headcount and grants made ; an increase in amortization of debt issuance costs and accretion of debt discount of $ 3.3 million due to the issuance of the 2024 notes ( see note 10 “ convertible senior notes ” to the consolidated financial statements ) ; an increase in amortization of deferred commissions of $ 13.3 million due to an increase in revenue ; a $ 23.3 million increase in noncash lease costs primarily due to the adoption of asc 842 effective january 1 , 2019 ; a decrease in benefit from deferred income taxes of $ 12.9 million primarily due to a decrease in valuation allowance due to the business acquisition made in 2018 ; a decrease in accounts receivable change of $ 19.7 million due to the timing of payments ; an increase in accounts payable and accrued liabilities changes of $ 4.0 million primarily due to the timing of compensation and other payments ; and an increase in deferred revenue change of $ 23.6 million due to higher billings .


 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.
     ```cash flows the following table sets forth a summary of our consolidated cash flows for the periods indicated : replace_table_token_23_th net cash flows provided by operating activities our net loss and cash flows from operating activities are significantly influenced by our investments in headcount and data center operations to support anticipated growth . our cash flows are also influenced by cash payments from customers . we invoice customers for the entire contract amount at the start of the term , and as such our cash flow from operations is also affected by the length of a customer contract . net cash provided by operating activities was $ 242.5 million in 2019 as compared to $ 184.7 million in 2018. the increase of $ 57.8 million was primarily due to : an increase in amortization of intangible assets of $ 4.5 million due to acquired businesses , and an increase in depreciation of fixed assets of $ 2.3 million due to an increase in capital expenditures ; an increase in stock-based compensation expense of $ 33.6 million due to the increase in headcount and grants made ; an increase in amortization of debt issuance costs and accretion of debt discount of $ 3.3 million due to the issuance of the 2024 notes ( see note 10 “ convertible senior notes ” to the consolidated financial statements ) ; an increase in amortization of deferred commissions of $ 13.3 million due to an increase in revenue ; a $ 23.3 million increase in noncash lease costs primarily due to the adoption of asc 842 effective january 1 , 2019 ; a decrease in benefit from deferred income taxes of $ 12.9 million primarily due to a decrease in valuation allowance due to the business acquisition made in 2018 ; a decrease in accounts receivable change of $ 19.7 million due to the timing of payments ; an increase in accounts payable and accrued liabilities changes of $ 4.0 million primarily due to the timing of compensation and other payments ; and an increase in deferred revenue change of $ 23.6 million due to higher billings .
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 Suspicious Activity Report : our platform and its associated solutions are sold to customers on a subscription basis and can be deployed through our unique cloud-based architecture that leverages both our global data centers as well as optional points-of-presence behind our customers ' firewalls . our flexible deployment model enables us to deliver superior security and compliance while maintaining the favorable economics afforded by cloud computing , creating a competitive advantage for us over legacy on-premises and cloud-only offerings . 35 we were founded in 2002 to provide a unified solution to help enterprises address their growing data security requirements . our first solution was commercially released in 2003 to combat the burgeoning problem of spam and viruses and their impact on corporate email systems . to address the evolving threat landscape and the adoption of communication and collaboration systems beyond corporate email and networks , we have broadened our solutions to defend against a wide range of threats , including email , mobile apps and social media , to protect the information people create from both compromise and compliance risks , and to archive and govern corporate information . today , our solutions are used worldwide to protect well over 100 million end users at enterprise customers , and millions more via service providers through our cloudmark division . as the threat environment has continued to evolve , we have dedicated significant resources to meet the ongoing challenges that this highly dynamic environment creates for our customers such as investing significantly to expand the breadth of our data protection platform as these expenditures are primarily in connection with the replacement and upgrade of equipment to lower the cost of deployment as well as to improve the efficiency for our cloud-based architecture . our business is based on a recurring revenue model . our customers pay a subscription fee to license the various components of our saas platform for a contract term that is typically one to three years . at the end of the license term , customers may renew their subscription and in each year since the launch of our first solution in 2003 , we have maintained a renewal rate with our existing customers of over 90 % . we derive this retention rate by calculating the total annually recurring subscription revenue from customers currently using our saas platform and dividing it by the total annually recurring subscription revenue from both these current customers as well as all business lost through non-renewal . we market and sell our solutions worldwide both directly through our sales teams and indirectly through a hybrid model where our sales organization actively assists our network of distributors and resellers . we also derive a lesser portion of our total revenue from the license of our solutions to strategic partners who offer our solutions in conjunction with one or more of their own products or services . our solutions are designed to be implemented , configured and operated without the need for any training or professional services . we offer various training and professional services for those customers that seek to develop deeper expertise in the use of our solutions or would like assistance with complex configurations or the importing of data . in some cases , we provide a hardware appliance to those customers that elect to host elements of our solution behind their firewall . increasing adoption of virtualization in the data center has led to a decline in the sales of our hardware appliances and a shift towards our software-based virtual appliances , which are delivered as a download via the internet . our hardware and services offerings carry lower margins and are provided as a courtesy to our customers . we expect the overall proportion of revenue derived from the hardware and services offerings to generally remain below 5 % of our total revenue . historically , the majority of our revenue was derived from our customers in the united states . we believe the markets outside of the united states offer an opportunity for growth and we intend to make additional investments in sales and marketing to expand in these markets . revenue from customers outside of the united states grew 32 % for the year ended december 31 , 2019 as compared to the prior year . in terms of customer concentration , there were two partners who accounted for 12 % and 11 % , respectively , of our total revenue in 2019. in 2018 and 2017 , one partner accounted for 12 % of our total revenue in each year . these partners sold to a number of end users , none of which accounted for more than 10 % of our total revenue in 2019 , 2018 and 2017. we have not been profitable to date and will need to grow revenue at a rate faster than our investments in cost of revenue and operating expenses in order to achieve profitability , as discussed in more detail below . key opportunities and challenges the total costs associated with the teams tasked with closing business with new customers and additional business with our existing customers have represented more than 90 % of our total sales and marketing costs since 2008. although we expect customers to be profitable over the duration of the customer relationship , the upfront costs typically exceed related revenue during the earlier periods of a contract . as a result , while our practice of invoicing our customers for the entire amount of the contract at the start of the term provides us with a relatively immediate contribution to cash flow , the revenue is recognized ratably over the term of the contract , and hence contributions toward operating income are limited in the period where the sales and marketing costs are incurred . accordingly , an increase in the mix of new customers as a percentage of total customers would likely negatively impact our near-term operating results . story_separator_special_tag for the software developed for use on our customers ' premises , the costs associated with the development work between technological feasibility and the general availability has not been material and as such we have not capitalized any of these development costs to date . sales and marketing . sales and marketing expenses include personnel costs , sales commissions , and other costs including travel and entertainment , marketing and promotional events , public relations and marketing activities . these costs also include amortization of intangible assets as a result of our past acquisitions . due to our continued investment in growing our sales and marketing operations , both domestically and internationally , headcount increases were reflected in higher compensation expense consistent with our revenue growth . our sales personnel are typically not immediately productive , and therefore the increase in sales and marketing expenses we incur when we add new sales representatives is not immediately offset by increased revenue and may not result in increased revenue over the long-term if these new sales people fail to become productive . the timing of our hiring of new sales personnel and the rate at which they generate incremental revenue will affect our future financial performance . we expect that sales and marketing expenses will continue to increase in absolute dollars and be among the most significant components of our operating expenses . general and administrative . general and administrative expenses consist of personnel costs , consulting services , audit fees , tax services , legal expenses and other general corporate items . as a result of our operational growth , we expect our general and administrative expenses to increase in absolute dollars in future periods as we continue to expand our operations and hire additional personnel . interest expense interest expense consists of interest expense and loss on conversion related to our convertible senior notes . other income , net other income , net , consists primarily of interest income earned on our cash , cash equivalents and short-term investments , and the net effect of foreign currency transaction gains and losses . ( provision for ) benefit from income taxes for most of the prior years , our income tax expense or benefit were primarily related to state and foreign income taxes . as we have incurred operating losses in all periods to date and recorded a full valuation allowance against our deferred tax assets , we had not historically recorded a provision for federal income taxes . however , in the year ended december 31 , 2017 , we recognized $ 0.2 million of deferred tax benefit in the u.s. related to amortization of tax goodwill on business acquisitions and $ 12.3 million of deferred tax benefit in the u.s. related to changes in the company 's valuation allowance resulting from the cloudmark , inc. and weblife balance , inc. business acquisitions . for the year ended december 31 , 2018 , we recognized $ 14.7 million of deferred tax benefit in the u.s. related to changes in the company 's valuation allowance resulting from the wombat security technologies , inc. acquisition . for the year ended december 31 , 2019 , we recognized $ 0.3 million of deferred tax benefit in the u.s. related to amortization of tax goodwill on certain business acquisitions . realization of any of our deferred tax assets depends upon future earnings , the timing and amount of which are uncertain . utilization of our net operating losses and research and development credits may be subject to substantial annual limitation due to the ownership change limitations provided by the internal revenue code and similar state provisions . analyses have been conducted to determine whether an ownership change had occurred since inception . the analyses have indicated that although ownership changes have occurred in prior years , the net operating losses and research and development credits would not expire before utilization as a result of the ownership change . in the event we have subsequent changes in ownership , net operating losses and research and development credit carryovers could be limited and may expire unutilized as a result of the subsequent ownership change . 41 results of operations the following table is a summary of our consolidated statements of operations . replace_table_token_9_th the following table sets forth our consolidated results of operations for the specified periods as a percentage of our total revenue for those periods . replace_table_token_10_th ( 1 ) includes stock-based compensation and amortization of intangible assets as follows : 42 replace_table_token_11_th revenue replace_table_token_12_th subscription revenue increased $ 170.6 million and $ 198.0 million , or 24 % and 39 % , respectively , for 2019 and 2018. these increases were due to a $ 128.6 million and $ 153.1 million increase in revenue from the united states and a $ 42.0 million and $ 44.9 million increase from international customers for 2019 and 2018 , respectively . the increases in subscription revenue for 2019 and 2018 were due to the ongoing demand for our solutions , increase in add-on activity and renewal rate being higher than 90 % . our enterprise customer count , which consists of customers that generate more than $ 10,000 in annual recurring revenue , increased from approximately 6,100 at the end of 2018 to approximately 7,100 , or 16 % , at the end of 2019. in addition , the number of customers with three or more products increased 38 % in 2019 as compared to 2018. our enterprise customer count increased from approximately 4,400 at the end of 2017 to approximately 6,100 , or 39 % , at the end of 2018. the revenue recognized from acquired deferred revenue related to the acquisitions we made was $ 5.8 million , $ 20.8 million and $ 3.2 million in 2019 , 2018 and 2017 , respectively . the change in subscription revenue due to pricing was not significant for either period . hardware and services revenue for

