Account-based marketing (ABM) is rooted in the premise that accounts are not all equal and must be prioritized. Account-based marketers must identify and communicate the criteria that define their top strategic accounts, whether that process begins by vetting recommendations from sales or conducting data analysis of existing customers and past deals. Accounts should be scored against three indexes — opportunity, achievability, and cooperation — to ensure the best chance of success. This tool outlines a methodology for selecting accounts for a large ABM program and provides examples of the insights that an account-based marketer should gather and apply to prioritize and score accounts.