There's a tonneau cover website that has a banner asking for people to call him before placing an order because he can save you money. You could just order the tonneau cover and pay without talking, but I thought what the hell?
I called and it's just the owner sitting in his warehouse. He explained that his contracts prevent him from quoting anything less in print, but over the phone I just told him which one I wanted and he said "That one? My margins kinda thin so I can only discount it by about 8% or so. That work for you?" Lowest price by a good amount and ended up ordering.
So not always a bad idea. I suppose the website screamed "I'm just a dude sitting in a warehouse waiting for you to call me and wouldn't know how to sell your info even if I wanted to."