Is this a fact or just speculation? I never remember him saying he worked for Gamestop
It's as good as fact, even if nobody can dig up a quote where he says exactly that. Benji is suspected to be the same person as BenVTrigger on VGC for good reason, and Ben was open enough in his time here to tell us how he gets his information. He works at a high enough manager position at Gamestop where he can look up country-wide sales of Gamestop in the company's system, that's why his statements and predictions concerning the US market have had good accuracy over the years. It's quite a big sample size for the US market, even though it's only one retail chain.