Loyalty reward programs are sales promotion strategies used by retail companies worldwide. Related to these programs, psychological questions arise as to what carries higher perceived benefits between price discounts and loyalty points. Another question is what is the most effective strategy for retail companies: price discounts or giving extra loyalty points? Determining which one of this strategies carries higher subjective value between cash and points rewards is also important. As such, numerous studies offer empirical evidence on the effects of loyalty reward programs. Consequently, the aim of this paper is to provide a comprehensive picture of the several research streams in these studies, summarize key findings, and indicate directions for future research.