"But," you say, "I can't afford to give my customers free soup to go."
Then you need to charge a little more. Because the impact of an unexpected "something extra" far outweighs the extra cost of providing it. I still remember when Amazon sent me an unannounced Christmas present (a travel mug we still use).
Note: I am not suggesting that you literally give your customers free soup. It could be a hat, a corkscrew, a T-shirt.
Make sure that the first gift (to a new customer) doesn't *create* an expectation of future gifts (because then it becomes an entitlement). By the same token, continue to surprise every customer from time to time. It's just memorable marketing (as opposed to the other kind).
Do you have any memorable marketing tactics to share? Leave a comment!