From what I've seen, a whole lot of really short boards. If that's ok for your application it's probably fine. Probably very loose, if any, control on color and quality. I don't know that a "flooring store" would be different. I buy my flooring from a mill in Michigan that lets me specify exactly what I want in terms of wood grade, color, figure quality, lengths and widths. I haven't seen that level of choice offered in any kind of store. It also tends to be inexpensive for the quality offered.

Hasn't anyone on this forum used solid hardwood flooring from Lowe's or Home Depot?

Thanks rwiegand for your reply.
Others, please chime in.