My tube site's new video player supports VAST and I'm just checking it out. I think it's probably all clean ads but I thought I would inquire if anyone knew about this. HTML5 players don't easily support the preroll ads my flash player did in the past. (as in not at all)
(Video Ad Serving Template (VAST) specification is a universal XML schema for serving ads to digital video players)
(Video Ad Serving Template (VAST) specification is a universal XML schema for serving ads to digital video players)