The development of competitive advantage has gained high interest in the current context of Covid-19 because many of the companies have been forced to temporary closures, the development of new strategies that differentiate them from their competitors has gained importance, since if they do not acquire and implement these strategies, clients will defect. Competitive advantage is an open field and involves the implementation of strategies so that they can achieve higher margins in the company. This review focuses on what the implementation of loyalty strategies represents, its construct, its importance, characteristics, and types of strategies for future research. A review of 34 bibliographic references was made, of articles published in academic journals from 2015 to the present, books by the main authors of the topics discussed as competitive advantage and loyalty strategies, as well as...