One reason Best Buy is still alive is that they effectively price discriminate between online buyers and in-store buyers.
I saw a deal for a 48” Vizio TV on bestbuy.com for $206 (in 2016, this was a screaming deal). I ordered for in-store pickup. When I went to the store, I saw the TV was listed for sale at $400 or so, with no indication of a better price online.
So Best Buy makes tons of money off folks who wander in, while doing good volume on online sales with lower margins.