Not sure if the technology works with the official BitTorrent Entertainment only or all the pirated ones as well, but check this out:
"YuMe Networks today announced it will launch the first ad campaign ever that allows a marketer to insert dynamically served video advertising within downloadable content.
YuMe’s ability to insert advertising within downloaded content and track the reach and frequency of a campaign across any device is a groundbreaking development in online advertising. It adds another monetization avenue for peer–to–peer sites, opens up new advertising opportunities for marketers, and could bring to consumers content that previously hasn’t been distributed on the Web because it was difficult to monetize.
YuMe utilizes video sensor technology to scour online video content, and then categorizes the video into customizable channels like Auto, Finance, Entertainment and Family Friendly. Advertisers can select the customized video channels that most closely match the brands, products and messaging in their advertising creative. YuMe attaches advertising to the selected content for delivery to any device – whether downloaded or streamed."
-- press release
Exent's Tech Puts Ads in Old, Pirated Games
Advertising Decoys on P2P Networks