Online video ads are leading to sales, according to the Online Publishers Association (OPA) "Frames of Reference: Online Video Advertising, Content and Consumer Behavior" report, conducted in partnership with OTX.

Of the 80% of viewers who had watched an online video ad, just over half had taken some sort of action. Nearly a third had checked out a Web site, while 22% had searched for more information, 15% had gone into a store and 12% had actually made a purchase.

Pam Horan of the OPA said, "With online video firmly entrenched in the mainstream, marketers need to understand what works for driving key advertising metrics."

PointRoll studied how online video advertising is relevant to brand marketers, and found that interactivity helps increase the time viewers spent with brands. When the video ad included or was surrounded by some form of interactivity — such as buttons to click to find out more or forms to fill out to register — it tended to increase average brand interaction time.