[ml1201]

I would say that for the thread creation and posting in your own thread things make it a chance to get an item from the prize set or whatever it is. Reason being is that I for instance will see a lot of threads already made for certain topics and then can't figure out what topic I want to make, and thus after making a certain amount and not reaching those goals I just tend not to bother. At least if its a percent chance people are going to be more likely to try if they don't post new threads as much.