The sheer amount of times I've clicked on a game and in the comments someone has provided a source to the correct numbers and this site has done nothing to fix them is staggering.
A couple quick examples, Tekken Tag 2 was said to have sold 1.3 million copies as of Jan 13 yet this site has it selling 1.1 million copies as of May 14. Naruto Storm 3 sold 1 million copies in US and Europe by May 13 yet Vgchartz has it selling 1.1 million copies worldwide as of May 14.
They're quick to fix hardware figures but game sales are left ignored even after sources are given and it should be a simple thing to change the numbers up so they're accurate.
Otherwise I just always question whether X game as really sold as much as they're saying. For a video game tracking site they don't really do a very good job.