A recent TubeMogul study sampled 25 video advertising major campaigns that ran identical videos within Facebook ad units and comparable click-to-play video ad units on publisher sites.  What they found is that Facebook as a top-ten video site is home to some of the most engaged viewers online.

For those interesting in getting the most of their video advertising efforts - artists, companies, and otherwise - the results of this study and the charts they developed suggest that Facebook might very well be your best bet: