I've written a blog post on this a few days ago, hopefully it's helpful ^{^} It's here (http://blog.stacck.com/2016/06/03/4-ideas-to-get-new-customers-in-your-restaurant/) but copying it below just in case :D

1. Bouncebacks A typical day for your business would comprise a hectic lunch crowd, followed by a lull in business in between, before the dinner crowd sets in. But wouldn’t it be much better if you could direct customers away from the peak hours, to eat at off-peak hours instead?

Bouncebacks are an underutilized tool that bounces guests from peak times to off-peak times and can also work to encourage frequency in your food and beverage operations.

Simple in theory and execution, this tactic can produce far more in revenues per dollar invested than traditional advertising. All you do is offer incentives to encourage your customer to try your restaurant during a non-peak shift. If you’re busy for lunch and need to drive sales for dinner, offer bounceback vouchers, or complimentary starters, that can only be redeemed during dinner hours.

1. Birthday Program People usually choose to eat out on their birthdays. This presents an opportunity for establishments with solid birthday restaurant promotion programs. Thing is, not many restauranteurs have taken advantage of this.

Designing a birthday program for returning customers will give you a perfect chance to swoop in and capture your increased share of the market. Chances are, they’d bring friends and family too!

1. “Toss Up Tuesdays” An extremely creative way to get more attention from repeat customers and new customers alike.

Pick Tuesdays (or your slowest food day) and give customers the chance to flip a coin. If they flip heads, they pay for their meal. If they flip tails, their meal is paid for by the house. All in all, guests will have a 50 percent chance of getting their food bill paid by the restaurant. This attracts your guests’ attention much more than a “buy one get one free” promotion, as it drives home an illusion of control. Guests are also more likely to have higher check averages than normal because there is a chance they won’t have to pay.

The unconventionalism of this strategy definitely helps generate tremendous attention.

1. Menu Bingo This is a great restaurant promotion for encouraging frequency and getting members to try different items on the menu. You simply create bingo cards that have different menu items in boxes. Have the cards designed with five columns and five rows. You can also promote other non-food items such as merchandise, cookbooks, and gift certificates. Guests have an allotted period of time – 60 days for example – to complete a connection just as they would with a bingo card. Once they try five items in any direction, they receive a free gift basket or other incentive that are roughly equal to one of the items purchased.

Hope this is useful for you!