I do at times support Bass Pro. One thing they HAVE done is mass advertising to very substantial numbers of people, through distribution of their multi page flyers. In the Fall, well over half of their flyer is full of guns.
This reintroduces the sight of guns to the general population in a positive light (hunting). No small dealer can match that kind of public presence.
This advertising also helps the local dealers, expanding the market and raising awareness. Sales will spill over to various dealers too, as people begin shopping around.
Also, for those that aren't aware, Bass Pro was limited to what guns/ammo they could sell because of limits put on them by their municipality. They wanted to sell handguns and have an onsite range too.