A couple of years ago I re-uploaded some popular and entertaining TV poker clips to test out the potential traffic with my URL in the description and in a video caption, one of them currently has 1.2m views and several others with 100k+. I don't have stats access anymore but it was sending v.low xx semi-targeted visitors a day so it can work to some extent.
If you make your own vids, the craze right now is obv. coaching so maybe offer up some lessons, tips, etc that'd interest your target and finish up with a plug for your product if it's related.
Anyway, as others have said.. if 2+2 catch on then it'll spread just fine.