This is one of github's cofounders, and the author of Pro Git, responding to other people's assessments of why github succeeded.
I can boil it down to exactly two reasons that happened to resonate with each other at the perfect frequency.
- GitHub started at the right time
- GitHub had good taste
Timing is everything. I remember when I first learned Git, and learned of GitHub. One, I had no idea of any alternatives to GitHub. Two, like many others new to them, I didn’t realize Git and GitHub weren’t just different names for the same thing.