I appreciate your reply. I had hoped it wasn't intended that way. It just caught me fresh off an exceptionally bad day at work.
As far as charging, I'm not really interested in monetizing MAST directly. I don't think the sales would be worth the effort, and attaching a cost would greatly reduce the reach this tool will have.
Now I do plan on fully monetizing a few model kits I have in the works that will be designed specifically for MAST. Anyone who downloads this tool will see my kits, so I will have a great advertising platform. I've put some thought into this =)
Btw, you only responded to my first paragraph. Does the idea of using a GroupID and the way I mentioned utilizing it go along with what you were suggesting?