This paper was prepared as background for a discussion held at the OECD in June 2016 on fidelity rebates. It explores why it is that firms use fidelity rebates, identifies some rationales that potentially benefit consumers (for example, these schemes often reduce prices, and can help to achieve efficiencies) and also identifies that they can sometimes harm consumers. It then examines the legal framework in which fidelity rebate cases take place, and identifies the objectives, standards and presumptions that determine the relevant assessment.