Digital media buyers are hungry for tools that make buying, management, and optimization simpler. Enter demand-side platforms (DSPs). DSPs improve the complex media buying technology stack by offering a nearly one-stop buying solution for programmatic media. However, DSP vendors' pitches can all sound alike, making it tough to know which one to choose. Forrester recommends a head-to-head testing approach for marketers who want to look under the hood and compare a couple of DSPs in action. This document provides simple rules and a detailed checklist to help you run a clean, successful head-to-head test.