I want to be able to infer and extrapolate from buying behavior. Suppose a customer buys at 1300hrs a certain plate, then at 1545hrs the same customer comes bac

I want to be able to infer and extrapolate from buying behavior. Suppose a customer buys at 1300hrs a certain plate, then at 1545hrs the same customer comes back for ice cream. Can I offer something specific for this customer? Can I award him for coming every day? How can I personalize his experience as a customer more? This of course, would be easier on a place that only have 2-5 customers, but alas, restaurants are usually rather crowded. Basically it's a Basecamp style web-app that needs to get done. For poker it's called PokerTracker. I am looking for RestaurantTracker.