Joystiq have covered a report by Jason Kraft and Chris Kwak at Susquehanna International Group indicating that the review scores of 275 titles from the past couple of years have very little to do with how a game does on market. Unfortunately, what does matter is something that most seasoned gamers rail against, and that's the strength of the brand. In release terms, that means sequels. From the article:
So what does affect sales? The best indicators of sales strength appear to be the strength of the publisher behind the game, the performance of prior iterations of the game (if it is a sequel) and the performance of the box-office sales of the movie version of the game.
I remember being harshly criticised for games reviews which didn't have a X out of 10 score at the end, which I always thought was rather stupid and lazy. Gauging the effort of the designers and the enjoyment of a game - indeed all of the various aspects of the gaming "experience" - with a pithy numeric seems to go against what it's all about. This is another argument for games journalists to take the helm and really examine the products they're reviewing as something more than a gadget to be tried and tested.