In today's retail landscape, the fight for customers is fiercer than ever. Loyalty programs may be the oldest marketing trick in the book, but they remain one of the most effective for getting consumers to stick with a company. Companies in industries from books to beauty products offer alluring perks and rewards for loyal customers. Several retailers offer loyalty programs offering customers perks and rewards for their continued shopping. We compiled 18 of the best loyalty programs in retail, comprising industries from books to clothing and beauty products. The loyalty programs offer customers free items, exclusive deals, and discounts on future purchases.