I saw an synopsis on them recently... and their view wasn't so much that Amazon was killing them off (though as somebody who doesn't have a car, I find Amazon insanely convenient) its just that they suck at customer relations and providing anything of real personal value.
The advantage a Best Buy has over something else is that they have people you can talk to and you can compare in person and judge for yourself. But if that advantage has been reduced to a near valueless "window shopping" then there isn't a point. If you could trust the the sales person to set you up real good (even if it costs a bit more) then you'll do it because you know you're getting reliable service.
Instead, Best Buy decided to race to the bottom... and it turns out, they lost!
Best Buy has always had trust problems... I've always been leery about going into there because I can't trust that the guys working the floor have any real knowledge. Best Buy, as a brand, is terrible. I think the "big box" can still work... you just can't be bad at it. Maybe the margins are so that you can't hire quality staff and keep them... if so then that's the way it goes... but it seems to me Best Buy's problems are entirely self-inflicted and if so, then I wouldn't be surprised if there is a smaller more reliable replacement in its wake... maybe not right away... but something.