There is definitely correlation if not causation.
http://vgchartz.com/forum/thread.php?id=4406
To find out, Mr. Schachter and his team reviewed data for more than 1,500 games released from 2002 to 2005, looking for correlations between sales and the games’ scores on Gamerankings.com, which compiles reviews from many publications and Web sites into a numeric verdict between 1 and 100. Their conclusion was simple: Top-rated games sell a lot more copies than bad ones.
...
To conduct apples-to-apples comparisons, I used the scores at Metacritic.com, which pulls together multiple reviews to give media products a score ranging from 1 to 100 that reflects the collective wisdom of professional critics.
The data was clear. The Top 10-selling games of last year — including titles like Gears of War and Guitar Hero 2 —had an average Metacritic score of 87.5. Only one of the top-selling games scored less than 80. (More about that later.) Meanwhile, the Top 10 box-office films of last year — including titles like “Pirates of the Caribbean: Dead Man’s Chest”’ and “X-Men: The Last Stand” — collected a poor average score of 62.9.
We don't provide the 'easy to program for' console that they [developers] want, because 'easy to program for' means that anybody will be able to take advantage of pretty much what the hardware can do, so the question is what do you do for the rest of the nine and half years? It's a learning process. - SCEI president Kaz Hirai
It's a virus where you buy it and you play it with your friends and they're like, "Oh my God that's so cool, I'm gonna go buy it." So you stop playing it after two months, but they buy it and they stop playing it after two months but they've showed it to someone else who then go out and buy it and so on. Everyone I know bought one and nobody turns it on. - Epic Games president Mike Capps
We have a real culture of thrift. The goal that I had in bringing a lot of the packaged goods folks into Activision about 10 years ago was to take all the fun out of making video games. - Activision CEO Bobby Kotick
