I will tell you one reason: Bitbucket is unbelievably slow where I live (Tokyo). Using it is mostly a matter of gnashing your teeth and waiting. GitHub is actu

I will tell you one reason: Bitbucket is unbelievably slow where I live (Tokyo). Using it is mostly a matter of gnashing your teeth and waiting. GitHub is actually painfully slow too; just not as slow. That's the main reason I pay GitHub and use them for those projects where I need something more than just a git server for collaboration.