By Caitlyn BohannonGraphs showing ad spend growth year-over-yearWith advertisers maintaining a significant focus on targeting the millennial demographic, Facebook’s and Twitter’s cost-per-thousand-impressions pricing trends increased to $4.90 in the third quarter of 2014.According to advertising solutions provider Ampush, an early adoption of video ad units drove an increase in CPMs, therefore causing a command for higher pricing. As competition for mobile ad inventory increases, a fight to hold the attentions of millennials can be best met on social in regards to mobile brands.“Ampush saw young consumers dominate mobile ad spend driven in part by mobile app and gaming advertisers, who continue to allocate significant budget towards reaching younger audiences,” said Jesse Pujji, co-founder and CEO at Ampush, San Francisco. “Moreover, the 13-17 age group was the least expensive to reach with a CPM of $2.87 in Q3 2014.“Rapid growth in ad spend is due to advertisers increasingly reaching people where they spend the most of their time; U.S. consumers use an average of three devices daily, and 60 percent of all Internet consumption is happening on mobile,” he said. “Advertisers are spending more on platforms that have the ability to reach consumers effectively, and require targeting, measurement, and content creation capabilities that span multiple screens.“These platforms consistently outperform those that do not have these unique attributes or targeting capabilities.”Ad spend growthWhile 60 percent of all Internet consumption now happens on mobile, and U.S. consumers using an average of three devices, reaching consumers effectively now requires targeting, measurement and content creation capabilities that span multiple screen.According to the report, CPM pricing, or cost per thousand impressions, on Facebook and Twitter increased 23 percent year-over-year to $4.90 driven by a continued adoption of high-performing mobile ad units. Also, mobile app install CPIs grew 29 percent to $3.48 year-over-year alongside increased competition for new users.Cost per clicks increased 53 percent year-over-year in Q3 in 2014. Broader adoption of optimized CPM bidding drove CPCs higher on Facebook, offset by improved conversion-keeping overall acquisition costs in check.Advertisers saw mobile app install CPIs grow 16 percent from Q2 to Q3 in 2014, largely due to increased competition for new users, and 29 percent year-over-year.Ampush believes that Twitter is still maturing as a platform but has promising use cases for highly customizable real-time marketing, new device targeting, keyword targeting, handle targeting, TV targeting and complementary advertising for smaller, more engaged audiences. As advertisers continue to increase spend and test new products, there is a huge opportunity for growth on the platform.Part of the movementAmpush gets to personally see these numbers grow.The in-feed solutions provider aims to give advertisers a single point of access to platforms that enable them to reach the right people with the right message at the right time, helping push ROI.Advertisers using Ampush’s AMP platform through the third quarter of 2014 increasingly embraced cross-platform mobile advertising, including an increase in mobile ad budgets. Mobile ad budgets increased by 233 percent in Q3 of 2014 compared to the comparable year-over-year period.This Ampush report is comprised of data from both Facebook and Twitter advertising campaigns, which was aggregated across a portfolio of advertisers leveraging the AMP platform to manage and scale their marketing budgets through Q3 in 2014. Ampush customers include leading direct response advertisers across gaming, ecommerce, travel, financial services, CPG and others.With continued expansion planned, Ampush preps for 2015 and hopes for another year of strong growth as it expands to new channels and more advertisers.“We've seen leadership in growth with performance-oriented brands in the mobile app, gaming, and e-commerce sectors,” Mr. Pujji said. “Ampush customers HotelTonight, Dollar Shave Club, GREE, Hyatt, and JackThreads are leading the way.”Final TakeCaitlyn Bohannon is an editorial assistant on Mobile Marketer, New York