A HUGE benefit of git (or any other distributed source code control system) is that the entire repository is stored in each developer’s environment. This means that you automatically have as many backups of the source code as you have developers. If you use a hosted service such as github, this means that even if github looses ALL of your data, you still have all your source code (and revision history) on your own machines.
In a software startup, your source code is like your crown jewels. Losing your source code can be disastrous.
This is primarily why I switched from svn to git, and why you should too.