During the last few decades, efforts to further customer-company relationships have become important due to increased competition in the consumer markets. One of the most popular strategies has been to introduce customer loyalty programs, which are believed to develop and enhance customer loyalty. The popularity of customer loyalty programs is based on the beliefs that loyal customers are very beneficial to a company and these programs would bond the customers to the company. More recently however, discussion over whether these statements are accurate has started to flourish. Loyal customers are not necessarily as profitable as believed and it is not easy for companies to gain competitive advantage because almost all companies have analogous customer loyalty programs. This thesis will evaluate a qualitative case study performed on ALK-Abelló, a global pharmaceutical company that specializes in allergen immunotherapy supplies. This thesis will determine whether their customer loyalty program manages to create and build loyalty among their customers, as well as analyze if a loyal customer is worthwhile for a company. A customer loyalty program is ultimately found to be a complement of customer loyalty alongside products, customer service and more.