As a followup to my local data breakdown, I thought I’d link to some other interesting findings:
Added 17/11/09: Marketing influences games more than ratings
Survey: Game Score-to-Sale Theory Again Disproven
A study from 2006 that concludes no correlation between sales & score.
When Pundits Attack: Game Sales vs Game Quality
This compares metacritic rating to overall sales for 1281 games during the PS2 era.
Each metacritic point is worth 7.7 extra sales per day
Some data extracted from between March 2007 & March 2008
The influence of metacritic on games sales
A more recent study from May 2009.