SteamSpy Accurancy?

hello, i just found steamspy.com and saw a lot of sales data of games (indie and AAA games), i’m wondering how accurate is the data from there ?

anynone knows ?

thanks in advance for all the help.

It is very accurate; 80%~90% of the “guesses”, the tracker is right… BUT, it doesn’t consider keys shared/sold neither bundle sales, there is where it falls apart.

thank you for the information BrUnO XaVIer