[graeme]

>Likewise if I have a neighbour who is a notorious liar tell me I can find a piece of equipment in a certain hardware store, should I be mad at the store owner when I don't find it there, or should I maybe be mad at my neighbour – the notorious liar?

If you are a store own, AND

1. People repeatedly coming in to your shop asking to buy something, AND

2. It is similar to the kinds of things you sell, from the suppliers you usually get supplies from, AND

3. You don't sell it

Then it sounds like your neighbour the notorious liar is doing profitable marketing for your business and sending you leads which you could profitably sell to, if you sold the item.

If there's a single customer who arrives via hallucination, ignore it. If there's a stream of them, why would you not serve them if you can profit by doing so?

There are obviously instances you'd ignore and you seem to be focussing on those rather than what OP was obviously talking about, repeat instances of sensible ideas

[carlosjobim]

I guarantee that most businesses have nothing against stocking or offering items that people come in and ask them for - but it has to be possible also. If you're asking for a Polish sausage in a hardware store because your neighbour sent you, then they probably don't have the licenses to sell food items, and probably their profit margin is higher selling hardware than selling sausages so they have no reason to start offering them.

There's usually a good reason why a business might not offer something that people think they should offer. Usually it is that they can't be profitable enough at a price point which customers will accept.