Everybody has probably heard about some project where management decided to motivate testers and programmers by rewarding testers for finding bugs and programmers for fixing them. In the absence of high ethical standards, this can devolve into the situation known to Dilbert fans as I'm gonna write me a new minivan.
I experimented with this idea once, over a decade ago. Well, not exactly this idea, but a variation of it: For each bug in my code which I fixed, I paid the tester who found it.
The risk here would be that I would intentionally resolve bugs as INVALID (or WONTFIX or anything other than FIXED) in order to avoid paying the penalty for fixing them, but I like to think that I made my decisions on their technical merits rather than based on my pocketbook. Since the tester saw the bug resolution, there was a degree of oversight: If I used bogus bug resolutions to avoid the bug fixing penalty, the tester would just reopen the bugs. The amount of the reward varied based on the quality of the bug, so that encouraged testers to focus on finding good bugs instead of weenie ones.
I think I paid out a few dozen bug rewards. (It was a small project.)