[Theodores]

Well...

Worked in a busy bike shop as a kid and sometimes you would have someone come through the door after a nut or bolt. I would go to the workshop and spend quite a bit of time finding the bolt, then I would only be able to charge 50p for it. By the time I had came back I could have used that time to serve a customer after some real purchases, e.g. a whole bicycle. There wouldn't even be any 'word of mouth' benefits, the bolt could be for a lawnmower or something and the customer could be far too wedded to their tin box vehicle for there to be the chance to upgrade them to a bicycle.

Anyway, it was not cost effective to do personal service bolt sales, at 50p a time, had I been smarter I would have had a big box of random bolts under the counter and made things 'self service'.