Licensing

I'm interested in this product but am a bit cloudy on how the licensing works.

Let's take Visio 2003 as an example. If I'm not using ThinApp (installing the program on the local disk) and need to make sure 30 PCs have Visio 2003, I would have to have 30 licenses for Visio 2003.

How does this work with ThinApp? Do I still have to have 30 Visio licenses?