Joel discusses running beta tests.

8. We have a policy of giving a free copy of the software to anyone who sends any feedback, positive, negative, whatever.

A while back I donated to the developer of an excellent donationware Mac app. Later the developer announced that the program was going to go to the next level, and become normal commercial software. I got into the closed beta of the new software, used the software often, gave feedback, and spotted several bugs. When the full version came out I got an email saying I could get a measly $4.50 off the purchase price. That was not what I was expecting. I still have not purchased the new version. (Go figure human nature, I get a discount coupon and get mad. )