← Glossary

A market segment of one

Treat the key account as a market: the wallet is the market size, your current sales are your share, and the gap is the prize.

The most useful thing a key account manager can do with a big customer is stop thinking of it as a customer. Think of it as a market with one buyer in it. The customer’s whole wallet for your category is the market size. Your current sales are your market share. The gap between the two is the prize, and it can be stated in one number that a board understands without a preamble.

The reframe changes the plan. Markets get strategies, segments, propositions and investment cases; customers get relationship reviews. Chapter 9 runs the same lens across a portfolio, where a segment of similar accounts is planned as one market, and the planning tool uses it as the opening question of every account: what is this customer worth to us, and what could they be worth?

Set out in full in: Creating Customer Value Propositions with AI (Kogan Page, 2027), chapters 8 and 9.

Related terms

See the method run on one real account in three days: the One Page Proposition.