[ben_straub]

Honestly, the reason is size. If you're a newcomer to OSS, it's very likely that you'll end up with a GitHub user account, and much less so with BitBucket.

We do mention BitBucket in the [forking workflows section](http://git-scm.com/book/en/v2/Distributed-Git-Contributing-t...), and many of the lessons from the GitHub chapter will carry over; the two sites have a lot in common.

[mhartl]

GitHub is indeed the 800 lb. Git gorilla in the OSS world, so I don't doubt that your main motivation is to serve the interests of your readers, but it's probably a good idea to disclose the potential conflict of interest (namely, that Pro Git coauthor Scott Chacon was GitHub's first employee and still works there).

[schacon]

I do actually cover this in the preface: https://github.com/progit/progit2/blob/master/book/preface.a...

The conflict of interest does bother me, so I did try to be as clear as I could about it and to point out at the beginning of the chapter that you could easily skip it if you don't like or don't want to use GitHub. I also stayed away from everything I could that required payment.

The truth is that I've been approached to write books specifically about GitHub for several years so I thought that the demand for that sort of information was high enough to warrant moving it to it's own chapter. Had I been approached about writing about other resources I would probably have also included them.

The more difficult decision was whether to include information on Gerrit. I actually started writing a section on it, then considered a chapter or appendix. The main deciding factor was how many people I thought might benefit from it.