Anybody interested in having people pay for their Unity3D-based games and tools may find this useful: http://www.forwardthinking.org.nz/paypal.html This is in Beta at the moment, and it would be good to test this in semi-real situations. We are already using it with the Virtual Lathe training tool. The basic functionality is that it allows a user to purchase a period of time of usage for the simulation. We can also allow organisations to bulk-buy licenses in advance and issue tokens so that they can give out licenses to, say, students doing online virtual training, who then can renew them themselves later if they need to. Likewise, special BuyNow buttons can be made for Channel Partners so that any purchase made through their website is tagged with their code and hence they can get part of the revenue generated. This can easily be added to pretty much any Unity3D code.