During my professional career as a developer most of the time I have been using Team Foundation Server (TFS) for source control. Back in the day I even used Source Safe, stone age history for most people. For my private project or small startup projects "the files on disk with occasional zip backups" approach has been way to common. I have also used different GIT solutions as well as Google Code. It works fine but when you are use to TFS it's not as easy as you are use to. All the mayor cloud suppliers want to flirt with the startup community by offering free services that will keep the startups close when they grow bigger. We have seen several examples of this from Microsoft in the past, like BizSpark. Now they offer free Team Foundation Server in the cloud called Team Foundation Service or Visual Studio Online. The basic account is free for up to five users with unlimited repositories. Support for both TFS and GIT repositories!
So far I have added two of my current projects and the performance is really good! There is also many ways to extend the service with your own code and REST APIs. You can also use free resources for builds, load testing and more. If you require more resources they can be purchased on a pay for what you use approach. If your project grows you can add additional team members for $20/month.