I generally agree with Sonicbeauty, save that it was not the attitude of dealers that did them in, it was the internet and world competition. Local dealers need a 35% profit margin (this was years ago when I was involved as a dealer). There is no way that internet sales needs such a margin. They can afford to give "deals" to customers state, nation, and even worldwide.
This is going to happen or has happened for most goods. I just bought a suitcase on the internet, as local prices are substantially higher and I can find just what I want, not just what local dealers choose to have. Restaurants, grocery stores, cars, and houses are all that is likely to resist this.
When I first used the internet in the 80s, I had no vision to see where all of this was to lead.