Loyalty programs are more popular than ever before. From 2013 to 2015, the number of loyalty program memberships increased 26% – reaching 3.3 billion in the process. The $48 billion industry is worth more than the video game and movie industries combined. While such rapid growth may catch some by surprise, retailers are well aware of loyalty programs’ impact on a company’s bottom line. After all, it can be five times more cost-effective to retain an existing customer than to acquire a new one.