Best Loyalty Programs?

Hi. My aunt has a small-business gift and novelty item store. She just recently moved to a new location and would like to offer a customer loyalty program for all customers. The only thing is, she's not sure about which company to use. Any ideas?
Kemperk...yes, she's earning enough of a profit. The thing is though, she was hoping for a punch-card type of loyalty program. Do you know of any such thing that would work?

excellent timing for your query; she should use, in my opinion, NO company but her own!

she should offer discounts as applicable, 2 for 1 and more

is she earning a profit, few such stores earn a profit