In recent years, Account-Based Marketing (ABM) has been the hottest topic for many corporate CMOs. 93% said it was either extremely or very important for future marketing plans. Since this report by Sirius Decisions in 2017, ABM has continued to dominate the global B2B marketing industry, with hardly any signs of a slowdown. Investments in ABM continue to take an increasing share of marketing investments. It is widely believed that ABM has become synonymous with best-practice B2B marketing in the sense of delivering the right message at the right time to the right people. And instead of a small budget item, ABM now forms the umbrella brand of the go-to-market strategy. As all companies strive to optimize the return on their marketing investments, the clear evidence that a well-implemented ABM strategy delivers significantly better results than many other activities makes the assumption inevitably so compelling. In this chapter, we define ABM, why it differs from conventional demand generation, explain the three types of ABM and provide a best-practice guide for successful implementation.