"I'm gonna make him an offer he can't refuse" 

"The Godfather" 1972

Do you have a mailing list?  (Or an email list?)  When you ask people to come to your shop, do they come?  If not, are you making them an offer that they can't refuse?  Are you following the 3 golden rules of making an offer?
1)  Introduce, or reintroduce yourself.  If you send out an email every month, this shouldn't be a problem.  What if you only send out email offers once every quarter?  Shouldn't you introduce yourself every time?  It could be as simple as Andy Jenkin's folksy, "Hi, this is your cousin Andy...." Once you remind people of how you met them, you are giving them a reason for your call, or letter.  If you haven't asked permission to send them offers, you are not a dear old friend, but a hawker.  If you have asked permission to contact them, you are just following up on your promise.  "Remember how I asked if it would be ok to let you know if I got in a great piece that might be of interest to you...well, I'm a man of my word, and I think that you are going to love this."

2)  Make the offer.  The offer should be big enough to attract their attention, and make it worth their while to come visit you.  I hate those coupon books that offer $1 off, or 10% off on a purchase.  It's not worth my time to even look at it, let alone drive to your shop.  Why in the world would I want to waste my time with your offer if it's not worth it?  It should be a big enough discount to capture my attention, and make me want to drive out of my way to your shop.  (You always need to know what your costs are, and make an offer that is profitable, and scalable.  I was doing some consulting for a Mexican restaurant.  Their offer was a free entree.  It wasn't "buy one, get one free", It wasn't "buy an entree, get a free dessert and drink".  It was a free entree.  There was no requirement to even buy a drink.  They lost their shirt on the deal, but it did give them a bunch of people that had never been to the restaurant that visited.  It's ok to make an offer like that, if you know your costs, but if you are not aware of the costs, you could lose money hand over fist, very quickly.

You also want to ask yourself what your lifetime value of your customer is, before you make the offer.  The Mexican restaurant might have lost money on that offer, but made money in the long run by gaining long term customers.
3)  You need a call to action.  If you have a great flier, or email letter, with a lot of information, but no call to action, you are wasting your time.  You should ask people to "come on down", because this is "This Weekend ONLY!", and if they do they will get "The deal of a lifetime!"

The call to action should accompany the offer (Perceived value higher than the cost of the trip), and be for a limited time.  If you don't have an expiration date on the offer, they can get it anytime that they want.  They don't have to come down right now, in fact, they don't really need to buy from you at all.

Instead it should clearly state the offer, and the expiration date, and an incentive for people to take action...right now.

When you combine these elements, you will have an offer that they can't refuse.

Reed Sawyer