Market your restaurant in social netwoking sites like facebook and foursquare. Restaurantry reservation widget can easily be embedded in your facebook page. Start accepting reservations from your facebook fans and followers. Other popular sites include Twitter,Google+,Youtube and Linkedln.
As a restaurant the primary goal of social networking presence is to build personal relationship with customers. You "post" something on facebook and all your facebook followers instantly get to know of this. Keep posting special menus, offers, events or anything else you think your fans would love. When you post one message it reaches to n followers in facebook, each of these followers shall forward same information to their followers and friends and so on spreading the message virally to a large population. Consequently this brings in word of mouth publicity and more and more table bookings for your restaurant. You will need to spend a few hours every week to do active social networking and reach more diners. Respond to your followers as much as you can. Upload videos to youtube.