Loyalty programs are used to acquire new customers, increase spending of existing customers, improve retention rates, and shift spending to higher margin products. There are now over 1.8 billion loyalty program memberships in the US, though many members are inactive. Relevance, reducing complexity, and reinforcing choices are key principles of loyalty marketing. Understanding customer profitability beyond just loyal customers is important, as the bottom 30% of customers can reduce overall profits. Future loyalty programs will focus on segmentation, tiering, broadening relationships across purchases, instant rewards, and coalition programs with multiple companies.