Yes, that's one thing that has to be carefully watched. When you incent someone to do something, they tend to do it. It's a bit of the "be careful what you wish for, you just might get it". Along with that is the disincentive which he did mention. He mentioned it more from a "don't embarrass someone" point of view but again - some people see it as an incentive. Some people are completionists and feel compelled to "get them all". You have to be careful not to encourage bad behavior.