Using current customer profitability to evaluate the market is internal thinking at its most poisonous.
One element you do not see in this table is customer profitability. This is one topic in which there is a substantial degree of confusion and theory abuse. For our purposes, it is sufficient to say that customer profitability is the net result of your strategy, not your starting point. How much money you make from doing business with a customer is a function of the value you deliver (which should be considered in your potential to grow analysis), the competitive landscape (considered in cost to grow), and how you position your organization to deliver and capture the value, which is under your control.
It makes no sense to include customer profitability under your current cost structure when the entire point of the exercise is to determine the right cost structure for the market. Using current customer profitability to evaluate the market is internal thinking at its most poisonous. This does not mean that customer profitability isn't important; it just means that it should dome later in the process.
ACTION POINT: Focus on determining the right cost structure for the market you want to serve.