I manage multiple Gamestop's.
And I'm willing to wager I know more about games than 95% of the posters on this site. That being said, there are some people who don't know tons about games that work in gaming retail, but are great sales people. The number one problem we run into are "hardore" gamers who think they know everything about games and try to disagree with everything we recommend or suggest. But I try and make sure I hire as balanced of employees as I can, and I make damn sure they aren't all core gamers.