Does anyone else think/know if game developers pay off critics for high review scores?

I just have that feeling. Ever since GTA 4 got a perfect 10 out of 10 on Gamespot I've been somewhat skeptic if all these hyped up games are reviewed on the same level. Don't get me wrong, I had plenty of fun with GTA. Now was it worth the 10 that it recieved? Questionable. I don't think I've ever played a game that deserved a perfect score. And now, Red Dead Redemption comes out. Fun game. Loads to do. Worth a 9.5? I'd say more of a 9.0, because of many very minor gameplay elements that weren't refined. Also, the lighting is great but it doesn't appear that they put too much effort into the polygons. Regardless, it seems every game that gets hyped up beyond belief before its release recieves inflated review scores. Do you think the developers actually pay these people for this? What are your opinions and/or factual knowledge?