It was part of the Wii boom. Videogames were suddenly big business and everybody wanted a piece. HMV started selling videogames, Sears actually started stocking them in their stores, Staples carried a small selection, Shopper's Drug Mart (Not sure if that is in the states) also got into the arena. But then, in the end years like 2012 and so on, when Wii was no longer selling like gangbusters and mobile gaming took the casual crowd, now these stores are shrinking back on their inventory or not even carrying it at all. HMV got rid of all their gaming stock. Sears seems to be doing the same.
I don't know why Staples is still trying to carry games although, when I stopped in today, they are really cutting back on the support of it. It was only two shelves worth of gaming space. I learned to start checking Staples for games when I went in one day and found out they were selling some and not only that, they had just marked down Pokémon Black and White to 18 something dollars and were clearing them out. Unfortunately, I missed out at that time but that experience taught me to always keep my eye on Staples. They eventually keep discounting titles to clear out remaining stock they have on it so I've gotten some pretty great deals on fairly new games. I don't get their business strategy but I'm on board for that part of it.