Generally customers are eager to signup for specials or customer exclusive deals. So rather than wasting money on other methods (for e.g. Groupon) to acquire new customers,  you can ask them to signup for your specials and become a loyal customer, on your own website & Facebook* (FB integration coming soon)

Here is how it looks.

So when a customer signs up for loyalty, the customer gets an acknowledgement email and you also get an email notification.