>>>We sell a VFP software (niche market) as a per seat license and one of our
>I would like to do this Wayne, but I can't. It's a big client and it's a multi country implementation. They have people using the soft once every 2 week and they don't want to pay a licence for each. I really need to find a pricing reference elsewhere to back my increase and propose something.

I like Mark's idea of a site license - or perhaps use the MS licensing and license the server. You will just have to roll your own as to what the charge should be per-server. In reality though, one terminal server box is only going to be able to maintain a certain number of concurrent users of your application - with this in mind, come up with a number you think a server can handle, and make the charge based on this. Then charge a monthly maintenance fee like Mark suggested.

Doing a per-server license would eliminate the need to build in checking in your application to ensure the maximum number of users in the system has not been exceeded.