Data mining, information/statistics selling Matt. While Google won't be selling your files, I'll bet my left nut that they're indexing and combing through them to augment the profile they have on you - and that is used to sell ads. Google is an ad company. Period.

Google could offer the service for free and I still wouldn't take them up on it. Likewise, if I was using a different service and it was suddenly acquired by either Google or Facebook, that data would be deleted immediately.