You fail to mention how GME went bankrupt twice in it's past. Did he say they would lose marketshare TO Gamestop, or just in general? BBY & other big boxes are growing quickly and do healthy softwear sales volumes.
I've seen EB chase GME out of high traffic malls before, ELBO has been and is, better run.
Try this just one time: go to BBY and shop for Consoles or Games. It's hopeless unless you hit it right. Staff all over the place but none of them play. And, Nintendo 64 is still in the test samples. Something is wrong with this big box retailer when it comes to video games. They may have lost focus due to the good sales of Digital Entertainment TV sets. GameSpot's web page has everything in stock both new and used. Say what you want about the old Babbages, but the store had early PC games that were astounding.
I absolutely agree that BBY is horrible in the softwear/video department, but if you open more doors & generage greater sales increases in a category than the industry as a whole, then you are stealing share from competitors. GME & ELBO are specialty retailers, BBY is more of a general consumer electronic retailer. GME & ELBO exist only because they can offer better services: first to market & customer service.
And a simple sales to market cap comparison actually has ELBO cheaper than GME, and ELBO is way over-priced. Longs will get hammered once MM support drops out from under GME. No,I'm not short, but I am considering it.
GME Sales 1.1B, Market Cap 1.1B Elbo sales 1.0B, Market Cap 0.9B