If you own a pet store, would you let visitors take photos of your pets?

Like most of you, I totally agree that there should be no reason why you cannot take photos of the pets on sale. This just doesn't make sense; if I were a store owner, I'd be happy to allow customers to take photos, it would be a form of free advertising and publicity for my business.
The only explanation I could think of, (besides the store owner being extremely short-sighted) is that the owner might be having animals whose sale is either illegal or restricted by law. He might not want to publicize the fact that he has species of illegal coral or fish in his saltwater aquariums, for example. This is just conjecture, so you never know what the true explanation might be short of asking him to tell it as it is.