I'm advising my company to upgrade our on-premise TFS 2008 to a newer version. As i see it, there are two options available to us: TFS 2013 (on-premise), or Visual Studio Online.

We are a small developer shop inside a larger (non-it) business, and would like to work internally and externally with a source control system. We have chosen to adopt the Microsoft stack, so other alternatives are not desired for us.

How do i compare the on-premise TFS2013 offering to Visual Studio Online? I'm concerned about costs, scaleabillty (up- and down), working with multiple parties, continuous integration builds, continuous deployment, unit- and integration tests. We develop mainly on BizTalk, WCF and some custom C# applications.

**Does anyone have advise or experience comparing these two offerings?**