This. While I don't know if they would do it if they were as popular as they want to be (maybe bitbucket desperately wants to charge but don't feel like they could compete if they did), I personally use bitbucket for this very reason.

Sometimes I also use bitbucket just to get away from hosting every single thing in Github. Nothing against Github (I use it quite a bit, and from what I've read their culture and ethics are good if not great), but regardless of their intentions, I'd rather not have one company monopolize mindshare