The poll is closed and I've posted the results in the first post, and will put them here too.
My take: It is hard to accurately determine what fan's reception to a game is. The only place I know that allows users to rank a game is Gamespot, and according to user ratings about 40,000 people gave GTA 4 an average vote of 9.1, and 50,000 people gave GTA SA a rating of 9.2. Obivously, people voting on a video game website don’t represent the general gaming population, and are instead those more devoted/invested in the industry. Still, according to about 40,000 people fan reception was similar for the 2 games, so I'm not sure how big of an impact that had on sales.
I think userbase certainly had some impact, as you can see in the original post, the sales of GTA 4 are down less than the sales of the PS3/360 compared to the PS2/Xbox. Maybe on a smaller userbase the platforms cannot support a game that both opens big and has big legs and thats why the sales of GTA 4 have slowed down faster than previous versions. I also think the choice "The Franchise peaked with San Andreas...", is partly responsible. The franchise is still huge, and will continue to be for a long time, but all franchise have to have a peak and I think San Andreas was it for the Grand Theft Auto franchise.
I don't think the "more competition in the 'sandbox' genre has much to do with it, as no other games in the genre have even approached the sales of the GTA franchise. I also agree that the "heightened awareness of mature content..." option had little if any influence on sales, although it may become a factor in the future.
So what do you think, do you agree with me, or the majority vote? Are you surprised by the votes each choice got, did you expect some of the answers to be closer together instead of one choice dominating the vote? Let us know what you think.
Also if you liked this thread, please keep a look out for another Change in Sales topic in a couple of days.