Like most human relations, you have to adapt to the situation. If the place is crowded, you might feel more obligated
to buy something even if it's just two ounces of bulk. If the place is crowded, and people seem to be actively shopping,
and you don't want to purchase anything, then maybe don't hang out long, just to clear the way for the active shoppers. However,
if you are a regular customer and there are few people there, you can hang out at will. It makes the place look popular, and
it may be clear from your conversation with the staff that you are a regular, and that may stimulate others to purchase items.
If the place is empty, likewise, hang out at will to keep the staff company; often this is the best time for questions and
discussions, no purchase necessary. Stay out of the way if staff is working, but otherwise, chat at will. If you can recommend
a tobacco or pipe to a customer, that helps the shop. But don't badger people. It takes some customers a long time and maybe
several visits to make a purchase.