Every customer that leaves your store is going to talk to a bunch of people. It’s not hard to get them to talk about you.
Put a conversation-starter in their hands.
A matchbook, a key chain, a free sample, a hat, a menu, a magnet, a pencil, a catalog, a button, a snack, a flyer. Check out photo of the goodie bag I got from the Paul Frank store.
It doesn’t matter what it is. It just needs to cause them to say, “I was just at ________ and they gave me this.” Word of mouth achieved!