traffic to our platform determines the number of ads we are able to show , affects the value of those ads to businesses and influences the content creation that drives further traffic ; as a result , our ability to grow our business depends on our ability to increase traffic on our platform . because we rely on internet search engines to drive traffic to our platform , a significant portion of our traffic can be affected by a number of factors , many of which are not in our direct control . changes in a search engine 's ranking algorithms , methodologies or design layouts may result in links to our website not being prominent enough to drive traffic to our website and mobile app . for example , in 2014 , google made changes to its algorithms and methodologies that may be contributing to the slowing of our traffic growth rate and the decline in traffic in the fourth quarter of 2014. google also recently announced that the rankings of sites showing certain types of app install interstitials could be penalized on its mobile search results page . while we believe the type of interstitial we currently use will not be penalized , the parameters of google 's policy may change from time to time , or may be poorly defined or inconsistently interpreted . as a result , google may unexpectedly penalize our app install interstitials , which may cause links to our website to be featured less prominently in google 's mobile search results page , and traffic to both our mobile website and mobile app may be harmed as a result . we can not predict the long-term impact of these changes . we also anticipate that our traffic growth will continue to slow over time , and potentially decrease in certain periods , as our business matures and we achieve higher penetration rates . as our traffic growth rate slows , our success will become increasingly dependent on our ability to increase levels of user engagement on our platform . this dependence may increase as the portion of our revenue derived from performance-based advertising increases . if user engagement decreases , our advertisers may stop or reduce the amount of advertising on our platform and our results of operations would be harmed . in addition , we also expect the cyclicality and seasonality in our business to become more pronounced as our growth rate slows , including weaker traffic in the fourth quarter of the year . increasing mobile usage . the number of people who access information about local businesses through mobile devices has increased dramatically over the past few years and is expected to continue to increase . although many consumers access our platform both on their mobile devices and through personal computers , we have seen substantial growth in mobile usage . we anticipate that growth in use of our mobile platform will be the driver of our growth for the foreseeable future and that usage through personal computers will continue to decline worldwide . while we currently deliver advertising on our mobile platform , the mobile market remains a new and evolving market with which we have limited experience . our continued success depends on , among other things , our efforts to innovate and introduce enhanced mobile products and features . if our efforts to develop compelling mobile advertising products are not successful , advertisers may stop or reduce their advertising with us . at the same time , we must balance advertiser demands against our commitment to prioritizing the quality of user experience over short-term monetization . if we are not able to balance these competing considerations successfully , we may not be able to generate meaningful revenue from our mobile products despite the expected growth in mobile usage , which would adversely impact our financial performance . ability to attract and retain local businesses . our revenue growth is driven by our ability to attract and retain local business advertisers that purchase our advertising products . our largest sales and marketing expenses consist of the costs associated with acquiring local business advertisers . we spent a majority of our sales and marketing expense for 2015 on initiatives related to local business advertiser acquisition and expect to continue to expend significant amounts to attract additional local business advertisers . at the same time , our local advertising agreements increasingly provide for performance-based cost-per-click payment terms , which may make it more difficult to forecast local revenue accurately . in addition , our advertisers typically do not have long-term obligations to purchase our products , and their decisions to renew depend on the degree of satisfaction with our products as well as a number of factors that are outside of our control , including their ability to continue their operations and spending levels . the small and medium-sized businesses on which we heavily rely often have limited advertising budgets and may be disproportionately affected by economic downturns . as a result , a worsening economic outlook would likely cause businesses to decrease investments in advertising , which could adversely affect our revenue . 45 investment in growth . we have invested aggressively in the growth of our platform and intend to continue to invest to support this growth as we expand the yelp platform , grow our communities and local business base , hire additional employees and further develop our technology . we also plan to invest in product development as we continue to innovate and introduce new advertising and e-commerce products , explore new platforms and distribution channels and develop partner arrangements that provide incremental value to our advertisers and business partners to encourage them to increase their advertising budgets allocated to our platform . we expect that these investments will increase our operating expenses , and that any increase in revenue resulting from product innovations will likely trail the increase in expenses . story_separator_special_tag this growth was driven primarily by purchases of cost-per-click advertising in 2015 , and by purchases of cost-per-impression advertising products in 2014. revenue from cost-per-click advertisers increased from 24 % of local revenue in 2014 to 50 % in 2015. in 2015 , 63 % of clicks were delivered on mobile compared to 54 % in 2014. our transactions revenue increased $ 38.6 million , or 736 % , in 2015 compared to 2014. the increase in 2015 was primarily the result of revenue from eat24 , which we acquired in february 2015. our brand revenue decreased $ 3.5 million , or 10 % , in 2015 compared to 2014 , and increased $ 6.5 million , or 23 % , in 2014 compared to 2013. the decrease in 2015 was primarily due to a decrease in the number of brand advertisers and our phase out of our brand advertising products . the increase in 2014 was primarily due to an increase in the average spend per brand advertiser , driven largely by increased advertising impressions per brand advertiser . as of the beginning of 2016 , we no longer offer brand advertising products . our other services revenue increased $ 7.9 million , or 43 % , in 2015 compared to 2014 , and $ 10.5 million , or 129 % , in 2014 compared to 2013. the increases in both years were primarily due to increases in revenue from added partnership arrangements and sales of remnant advertising inventory . cost of revenue our cost of revenue consists primarily of network costs , credit card processing fees and web hosting , as well as salaries , benefits and stock-based compensation expense for our infrastructure teams related to operating our website and mobile app . it also includes costs associated with video production and creative design for brand advertising . replace_table_token_16_th cost of revenue increased $ 26.6 million , or 109 % , in 2015 compared to 2014 , and $ 7.8 million , or 47 % , in 2014 compared to 2013. the increases in 2015 and 2014 were primarily attributable to increases of $ 11.8 million and $ 4.3 million , respectively , in outside hosting and internet service fees , which are necessary to support the increase in visitors to our website and transactions completed on our website . set up costs , including video production , for active local business listing pages also increased by $ 0.3 million and $ 0.4 million in 2015 and 2014 , respectively , due to increased demand by local businesses for video on their business listing pages . expenses related to creative design for brand and local advertising customers also increased by $ 2.2 million and $ 0.7 million in 2015 and 2014 , respectively , and we added personnel to support our website infrastructure resulting in increases of $ 0.3 million and $ 0.4 million in 2015 and 2014 , respectively . in addition , merchant fees related to credit card transactions increased by $ 9.1 million and $ 2.0 million in 2015 and 2014 , respectively . the increase in 2015 was primarily due to the acquisition of eat24 in february 2015 combined with the growth in local revenue . cost of revenue also increased by $ 2.9 million in 2015 compared to 2014 as a result of third-party food delivery related costs associated with eat24 . 52 sales and marketing our sales and marketing expenses primarily consist of salaries , benefits , travel expense and incentive compensation expense , including stock-based compensation expense , for our sales and marketing employees . in addition , sales and marketing expenses include business acquisition marketing , community management , branding and advertising costs , as well as allocated facilities , insurance , business taxes and other supporting overhead costs . our focus to date has been on organic and viral growth driven by the community development efforts of our community management team , which is responsible for growing and fostering local communities , as well as coordinating events to raise awareness of our brand . as a result , we historically incurred minimal sales and marketing expenses to acquire organic traffic to our platform . however , we launched our first television advertising campaign in 2015 , and plan to continue investing in various advertising channels in 2016. we expect our community management costs to increase as we continue to expand our communities . we expect our sales and marketing expenses to increase as we develop our communities , increase the number of local advertising accounts and continue to build our brand . the majority of these expenses will be related to hiring sales employees and community managers , as well as costs incurred with various third party media outlets and other advertising channels . we expect sales and marketing expenses to increase and to be our largest expense for the foreseeable future . replace_table_token_17_th sales and marketing expenses increased $ 100.7 million , or 50 % , in 2015 compared 2014 , and $ 69.1 million , or 52 % , in 2014 compared to 2013. the increases in 2015 and 2014 were primarily attributable to the additional salaries , benefits , travel and other related expenses resulting from increased headcount of $ 57.1 million and $ 42.9 million , respectively , including increases in stock-based compensation expense of $ 6.9 million and $ 5.0 million , respectively , as we expanded our sales organization to take advantage of the market opportunity created by increased recognition of the value of our advertising products and increased use of our free online business accounts . as a result of our increases in net revenue , our commission expenses increased $ 2.7 million and $ 5.2 million in 2015 and 2014 , respectively . in addition , we experienced increases in facilities , insurance , business taxes and other related allocations of $ 17.1 million and $ 11.8 million in 2015 and

cash flows the following table summarizes our cash flows for the periods indicated : replace_table_token_29_th operating activities . we generated $ 57.4 million of cash in operating activities in the year ended december 31 , 2015 , primarily resulting from our net loss of $ 32.9 million , which included non-cash depreciation and amortization expenses of $ 29.6 million , non-cash stock-based compensation expense of $ 60.8 million , non-cash provision for doubtful accounts of $ 16.8 million and a $ 20.3 million expense related to a valuation allowance recorded against certain domestic and foreign deferred tax assets . in addition , significant changes in our operating assets and liabilities resulted from the following : ● increase in accounts receivable of $ 25.3 million due to an increase in billings for local advertising plans , as well as the timing of payments from these customers ; ● increase in accounts payable , accrued expenses and other liabilities of $ 15.9 million related to the growth in our business , increase in eat24 restaurant payable , accrued vacation and employee-related expenses , and the timing of invoices and payments to vendors ; and ● increase in prepaids and other assets of $ 22.7 million relating to an increase in prepayments ( primarily for marketing and business licenses ) and deferred tax benefits . we generated $ 57.9 million of cash in operating activities in the year ended december 31 , 2014 , primarily resulting from our net income of $ 36.5 million , which included non-cash depreciation and amortization expenses of $ 17.6 million , non-cash stock-based compensation expense of $ 42.3 million , non-cash provision for doubtful accounts of $ 7.2 million and a $ 28.2 million increase related to our release of valuation allowance previously recorded against certain domestic and foreign deferred tax assets .


 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 summarizes our cash flows for the periods indicated : replace_table_token_29_th operating activities . we generated $ 57.4 million of cash in operating activities in the year ended december 31 , 2015 , primarily resulting from our net loss of $ 32.9 million , which included non-cash depreciation and amortization expenses of $ 29.6 million , non-cash stock-based compensation expense of $ 60.8 million , non-cash provision for doubtful accounts of $ 16.8 million and a $ 20.3 million expense related to a valuation allowance recorded against certain domestic and foreign deferred tax assets . in addition , significant changes in our operating assets and liabilities resulted from the following : ● increase in accounts receivable of $ 25.3 million due to an increase in billings for local advertising plans , as well as the timing of payments from these customers ; ● increase in accounts payable , accrued expenses and other liabilities of $ 15.9 million related to the growth in our business , increase in eat24 restaurant payable , accrued vacation and employee-related expenses , and the timing of invoices and payments to vendors ; and ● increase in prepaids and other assets of $ 22.7 million relating to an increase in prepayments ( primarily for marketing and business licenses ) and deferred tax benefits . we generated $ 57.9 million of cash in operating activities in the year ended december 31 , 2014 , primarily resulting from our net income of $ 36.5 million , which included non-cash depreciation and amortization expenses of $ 17.6 million , non-cash stock-based compensation expense of $ 42.3 million , non-cash provision for doubtful accounts of $ 7.2 million and a $ 28.2 million increase related to our release of valuation allowance previously recorded against certain domestic and foreign deferred tax assets .
```    
 Suspicious Activity Report : traffic to our platform determines the number of ads we are able to show , affects the value of those ads to businesses and influences the content creation that drives further traffic ; as a result , our ability to grow our business depends on our ability to increase traffic on our platform . because we rely on internet search engines to drive traffic to our platform , a significant portion of our traffic can be affected by a number of factors , many of which are not in our direct control . changes in a search engine 's ranking algorithms , methodologies or design layouts may result in links to our website not being prominent enough to drive traffic to our website and mobile app . for example , in 2014 , google made changes to its algorithms and methodologies that may be contributing to the slowing of our traffic growth rate and the decline in traffic in the fourth quarter of 2014. google also recently announced that the rankings of sites showing certain types of app install interstitials could be penalized on its mobile search results page . while we believe the type of interstitial we currently use will not be penalized , the parameters of google 's policy may change from time to time , or may be poorly defined or inconsistently interpreted . as a result , google may unexpectedly penalize our app install interstitials , which may cause links to our website to be featured less prominently in google 's mobile search results page , and traffic to both our mobile website and mobile app may be harmed as a result . we can not predict the long-term impact of these changes . we also anticipate that our traffic growth will continue to slow over time , and potentially decrease in certain periods , as our business matures and we achieve higher penetration rates . as our traffic growth rate slows , our success will become increasingly dependent on our ability to increase levels of user engagement on our platform . this dependence may increase as the portion of our revenue derived from performance-based advertising increases . if user engagement decreases , our advertisers may stop or reduce the amount of advertising on our platform and our results of operations would be harmed . in addition , we also expect the cyclicality and seasonality in our business to become more pronounced as our growth rate slows , including weaker traffic in the fourth quarter of the year . increasing mobile usage . the number of people who access information about local businesses through mobile devices has increased dramatically over the past few years and is expected to continue to increase . although many consumers access our platform both on their mobile devices and through personal computers , we have seen substantial growth in mobile usage . we anticipate that growth in use of our mobile platform will be the driver of our growth for the foreseeable future and that usage through personal computers will continue to decline worldwide . while we currently deliver advertising on our mobile platform , the mobile market remains a new and evolving market with which we have limited experience . our continued success depends on , among other things , our efforts to innovate and introduce enhanced mobile products and features . if our efforts to develop compelling mobile advertising products are not successful , advertisers may stop or reduce their advertising with us . at the same time , we must balance advertiser demands against our commitment to prioritizing the quality of user experience over short-term monetization . if we are not able to balance these competing considerations successfully , we may not be able to generate meaningful revenue from our mobile products despite the expected growth in mobile usage , which would adversely impact our financial performance . ability to attract and retain local businesses . our revenue growth is driven by our ability to attract and retain local business advertisers that purchase our advertising products . our largest sales and marketing expenses consist of the costs associated with acquiring local business advertisers . we spent a majority of our sales and marketing expense for 2015 on initiatives related to local business advertiser acquisition and expect to continue to expend significant amounts to attract additional local business advertisers . at the same time , our local advertising agreements increasingly provide for performance-based cost-per-click payment terms , which may make it more difficult to forecast local revenue accurately . in addition , our advertisers typically do not have long-term obligations to purchase our products , and their decisions to renew depend on the degree of satisfaction with our products as well as a number of factors that are outside of our control , including their ability to continue their operations and spending levels . the small and medium-sized businesses on which we heavily rely often have limited advertising budgets and may be disproportionately affected by economic downturns . as a result , a worsening economic outlook would likely cause businesses to decrease investments in advertising , which could adversely affect our revenue . 45 investment in growth . we have invested aggressively in the growth of our platform and intend to continue to invest to support this growth as we expand the yelp platform , grow our communities and local business base , hire additional employees and further develop our technology . we also plan to invest in product development as we continue to innovate and introduce new advertising and e-commerce products , explore new platforms and distribution channels and develop partner arrangements that provide incremental value to our advertisers and business partners to encourage them to increase their advertising budgets allocated to our platform . we expect that these investments will increase our operating expenses , and that any increase in revenue resulting from product innovations will likely trail the increase in expenses . story_separator_special_tag this growth was driven primarily by purchases of cost-per-click advertising in 2015 , and by purchases of cost-per-impression advertising products in 2014. revenue from cost-per-click advertisers increased from 24 % of local revenue in 2014 to 50 % in 2015. in 2015 , 63 % of clicks were delivered on mobile compared to 54 % in 2014. our transactions revenue increased $ 38.6 million , or 736 % , in 2015 compared to 2014. the increase in 2015 was primarily the result of revenue from eat24 , which we acquired in february 2015. our brand revenue decreased $ 3.5 million , or 10 % , in 2015 compared to 2014 , and increased $ 6.5 million , or 23 % , in 2014 compared to 2013. the decrease in 2015 was primarily due to a decrease in the number of brand advertisers and our phase out of our brand advertising products . the increase in 2014 was primarily due to an increase in the average spend per brand advertiser , driven largely by increased advertising impressions per brand advertiser . as of the beginning of 2016 , we no longer offer brand advertising products . our other services revenue increased $ 7.9 million , or 43 % , in 2015 compared to 2014 , and $ 10.5 million , or 129 % , in 2014 compared to 2013. the increases in both years were primarily due to increases in revenue from added partnership arrangements and sales of remnant advertising inventory . cost of revenue our cost of revenue consists primarily of network costs , credit card processing fees and web hosting , as well as salaries , benefits and stock-based compensation expense for our infrastructure teams related to operating our website and mobile app . it also includes costs associated with video production and creative design for brand advertising . replace_table_token_16_th cost of revenue increased $ 26.6 million , or 109 % , in 2015 compared to 2014 , and $ 7.8 million , or 47 % , in 2014 compared to 2013. the increases in 2015 and 2014 were primarily attributable to increases of $ 11.8 million and $ 4.3 million , respectively , in outside hosting and internet service fees , which are necessary to support the increase in visitors to our website and transactions completed on our website . set up costs , including video production , for active local business listing pages also increased by $ 0.3 million and $ 0.4 million in 2015 and 2014 , respectively , due to increased demand by local businesses for video on their business listing pages . expenses related to creative design for brand and local advertising customers also increased by $ 2.2 million and $ 0.7 million in 2015 and 2014 , respectively , and we added personnel to support our website infrastructure resulting in increases of $ 0.3 million and $ 0.4 million in 2015 and 2014 , respectively . in addition , merchant fees related to credit card transactions increased by $ 9.1 million and $ 2.0 million in 2015 and 2014 , respectively . the increase in 2015 was primarily due to the acquisition of eat24 in february 2015 combined with the growth in local revenue . cost of revenue also increased by $ 2.9 million in 2015 compared to 2014 as a result of third-party food delivery related costs associated with eat24 . 52 sales and marketing our sales and marketing expenses primarily consist of salaries , benefits , travel expense and incentive compensation expense , including stock-based compensation expense , for our sales and marketing employees . in addition , sales and marketing expenses include business acquisition marketing , community management , branding and advertising costs , as well as allocated facilities , insurance , business taxes and other supporting overhead costs . our focus to date has been on organic and viral growth driven by the community development efforts of our community management team , which is responsible for growing and fostering local communities , as well as coordinating events to raise awareness of our brand . as a result , we historically incurred minimal sales and marketing expenses to acquire organic traffic to our platform . however , we launched our first television advertising campaign in 2015 , and plan to continue investing in various advertising channels in 2016. we expect our community management costs to increase as we continue to expand our communities . we expect our sales and marketing expenses to increase as we develop our communities , increase the number of local advertising accounts and continue to build our brand . the majority of these expenses will be related to hiring sales employees and community managers , as well as costs incurred with various third party media outlets and other advertising channels . we expect sales and marketing expenses to increase and to be our largest expense for the foreseeable future . replace_table_token_17_th sales and marketing expenses increased $ 100.7 million , or 50 % , in 2015 compared 2014 , and $ 69.1 million , or 52 % , in 2014 compared to 2013. the increases in 2015 and 2014 were primarily attributable to the additional salaries , benefits , travel and other related expenses resulting from increased headcount of $ 57.1 million and $ 42.9 million , respectively , including increases in stock-based compensation expense of $ 6.9 million and $ 5.0 million , respectively , as we expanded our sales organization to take advantage of the market opportunity created by increased recognition of the value of our advertising products and increased use of our free online business accounts . as a result of our increases in net revenue , our commission expenses increased $ 2.7 million and $ 5.2 million in 2015 and 2014 , respectively . in addition , we experienced increases in facilities , insurance , business taxes and other related allocations of $ 17.1 million and $ 11.8 million in 2015 and

