In the real world, programmers deploy a preliminary release of the program called a beta release. People then use the beta release and test it for errors. As errors are reported to you, they are then fixed. The way to get people to act as "beta testers" is usually to offer them a copy of the final version for free or to have a department in your company test it. Many programmers also distribute their beta releases on the Internet or online BBSes, allowing users to try the beta release for free. As a last resort, it’s not uncommon to pay people to serve as beta testers. To my knowledge there was only one occasion in 1998 in which a program was sold as a beta release. This isn’t an advisable option, as many users will be ticked off at being charged for a program that’s still being tested.