A study released by TubeMogul at OMMA Video in New York, "studied 25 major video advertising campaigns that ran identical videos within Facebook ad units (four types) and comparable click-to-play video 300x250 ad unitss on publisher sites, we compared resulting cost, viewing-time and much more. The sample spans 60.2 million views. Brands include Symantec, Microsoft, Hyundai, 20th-Century Fox and more. Facebook ad types span in-application display ads, interstitials and virtual currency placements, as well as some numbers for their official "Sponsored Video" unit," revealed the Study.
Someone watching a video on Facebook is likely to spend 1:45 minutes on the ad, whereas a viewer on Bing will only give it 1:16 minutes. In between those two ends of the spectrum, Yahoo garners an average 1:28 minutes of retina time, Google 1:32 and Twitter 1:44, right behind Facebook.