Next Generation has an article up looking at a report from SIG, on the correlation between game reviews and sales. Their findings indicate that, while reviews obviously do have some effect on games sold, there just isn't that much of a correlation
. From the article: "He said he doubted that publishers and PRs would stop caring about review scores, especially as they matter a lot with consumers who compare games from the same sub-genre — say, basketball games. But he said that, as with last year's report, the report's findings are unlikely to be popular. 'We received a lot of attention but the stats do not lie,' he said."