• by Tyler Loechner  @mp_tyler, June 12, 2014

Mobile ad exchange Nexage on Thursday revealed that 35% of the inventory available for real-time bidding (RTB) on its exchange is either interstitials, rich media or video ad formats. These three formats will represent over 50% of all mobile inventory by next year if current growth rates hold.

Video is the fastest-growing of the three, with 516% more video ads being available for programmatic buying in Q1 2014 compared to Q1 2013. However, Rich Media units (346% more) and interstitials (194%) were no strangers to growth either.

The number of ads delivered matched the supply growth, with 404% more mobile video ads being delivered through Nexage in Q1 2014 compared to Q1 2013. Rich Media (216% more) and interstitials (178%) also grew.

The use of more “advanced” ad units is representative of the maturation of the mobile RTB market. Nexage attributes the growth to “creative talent [being] applied to mobile-specific ads as advertisers and agencies aggressively embrace mobile.”

The reason behind marketers' increased interest in Rich Media, interstitial and video ad formats is clear: Nexage says consumers were 26 times more engaged with expandable banners (Rich Media) than static banners, while interstitials drew eight times more engagement static banners. This data comes from Celtra, a Nexage partner.

Celtra also said Rich Media banners saw a nine times increase in click-through compared to their static counterparts, while interstitials had eight times more clicks.