Site MGS and MGS2 discrepancy?

[Kayanator]

Kayanator said:

d21lewis said:
Maybe some sites include the XBOX version of MGS2, or the Cube version of MGS. All I know is Wiki is wrong quite often because video game companies notoriously edit their own info.

Here's a source regarding the original games sales. 6.6 million according to gamespot. (there are many other sources with the same number but gamespot is the most credible.)

http://www.gamespot.com/ps2/adventure/metalgearsolid2sonsol/news.html?sid=2847978

Also TTS for the GameCube bombed horribly so it does not account for a million in sales.

As for MGS2 sales here is one source which also reaffirms the above numbers

http://www.gameguru.in/features/2007/07/mixed-bag-metal-gear-solid-vs-splinter-cell-conviction/

 and another. http://www.gameplanet.co.nz/mag.dyn/Features/1751.html

These are just a couple.

I'd like to know where this site get's its sources on MGS games?