They have what I want and I can walk out the door with it right then. They generally have a drawer of take-off stems I can rummage through to find something that fits for $10-15. A couple have been in business for a while, and might have a random bit or bob that I need for an old bike in a coffee can somewhere in the basement. Also I hate clothes shopping online.
That is about it. They are a service provider to me, nothing more, nothing less. I will gladly use them if they can provide what I need for a price I am willing to pay, just like any other business out there.