I'm a paying GitHub customer and having big projects like Ruby on Rails and Perl hosted there makes me very comfortable. I figure if they can handle the big stuff, they can handle me! Plus, I use as much free software as everyone else and am happy to help out indirectly (by being a paying customer).

I expect prices will rise soon as well. I'm not sure anyone has mentioned this yet, even though it seems inevitable. Still, I think GitHub is fantastic and I'm planning to increase my usage.