I've been using github for quite a while for working against open-source code bases, but continued to use my own git installation for private repositories; and I did this because of their pricing model.
Their UI is very nice, and their features unbeatable, but I'm not a company with a handful of products who wants to facilitate collaboration with an internal dev team, I want to store a bunch of small repositories, and maybe privately collaborate with a small number of people sporadically. Even with their highest self-subscribing plan (at $22/month) you only get 20 private repositories.
This morning I received an email from bitbucket, purporting to -- among a swath of other new features -- rock git(my preferred DVCS). This makes them a viable alternative for consolidating both my open repositories -- that I would usually use github for -- and repositories that I host on my private server.
Along with their new features the pricing model fits my use-case perfectly; their FREE plan has unlimited private repositories with 5 private collaborators. As the price increases the number of collaborators that can view and edit your private repositories increases; which seems simple and fair.
I really want to love -- and use -- github, and if they would provide a cost-effective plan with unlimited repositories (even if it was still size limited as it is now) I would definitely take them up on it.
As Atlassian continues to progress bitbucket and bring feature-parity with github, hopefully this new direct competition with motivate github to be a little more competitive price-wise.