Every time a new person walks in the door, your front of the house personnel (hostess or servers) should have been trained by you to approach them and ask them if this is their first time in your restaurant.
"Is this your first time in our restaurant?  Well let me tell you about us..."Ask your staff to pitch about the restaurant, about you, how did you started, where did you get the recipes, anything that it's personal and differentiates your restaurant from your competitors (and by the way, this is the perfect place to pitch your Unique Selling Proposition to your potential and future clients.)The purpose of this buyer education is to create brand loyalty. Once your clients build a relationship with your restaurant, they are more likely to visit your place than your competitor's. By knowing more about you and your business, you personalize their relationship and their loyalty with your restaurant.This is why it's also a good idea to have an online (or printed) quarterly or bimonthly newsletter so that you can give your clients interesting information about your place, your staff and your cuisine.