In planning sessions, much time is usually spent defining target markets, reviewing sales histories and projections, new product schedules, what customers were doing with competitors, and so on. Sometimes there is discussion about what truly differentiates you from your competitors, what makes you unique, but not often enough.
Why not take it a step even further, and ask who amongst your customers would be in trouble if you suddenly closed up shop, why, and how long it would take them to find an appropriate substitute.
If you manage to answer those questions, you may have succeeded in defining what makes you truly different in the way that you add value to your customers.
In the event that you cannot identify a customer who would miss you for longer than it took to pick up the phone and call a competitor, you need to consider how you can change this before you disappear.