I'm just a player, I have not GM'd any of these scenarios, but to give GM's incentive to report their games might include something like GM xp... I frequent the boards on Jinx.com and they have a system where if you use their forums you get 'shopper xp' I guess you could call it, and more if you take their trivia quizzes.
My thought is to have them gain xp for what they have reported so far, and continue with it as they report more, and then as they gain GM prestige they get swag and then coupons for paizo products too.
I know that it's similar to what many are saying here but I keep waiting every week on the Jinx website to take their quizzes so I can get to the next level and I'm not called an 'initiate' or something (and discounts on anything is nice too). and I'm not trying to advertise for their clothes, I think it's a good model for geeks and the 'oohh shiny' factor that we all have. Like Doug Doug was saying he can compare his GM-ness with others and it'll be a quicker way to do so. maybe it will get other GM's wanting to be the one with the most games run under their belt and reported proper-like.
My Gm has been really good about reporting all our games, but we mostly play in home games.
