Stealth Street Addresses

The other day I was driving around in an unfamiliar part of town, trying to find a used book store. I had the street address, but that wasn't terribly helpful, because for some unknowable reason, none of the commercial buildings had visible numbers.

Is this some sadistic collusion on the part of business owners, hoping that if people slow down to try and find the address somewhere visible, that maybe some of us will decide to stop at their establishments? It makes no sense to me why a business would not do whatever it took to make their location easy to find.

How hard is it to slap some numbers on the building, door or window, so that customers who are actively seeking you, have a chance to actually find you?

I did eventually find the place I was looking for, and found that they had gone out of business. Lesson learned: CALL before driving across town at 4:00 pm, otherwise you may end up wasting time/gas.