Why are the people who could be our customers not our customers?
Frederick Reicheld famously argued that asking your customers if they would recommend you is a powerful metric - and I would agree. But I don't think it's the only question we need to ask. Especially so because there's a whole group of people who tend to get overlooked.
What about those people who are not your customers but could be? Do we do enough to understand what's stopping them engaging with us in the first place?
Knowing why they never entered our store, visited our web site or completed a transaction is, I'd argue, the most important thing we need to understand.