What's your TESLA? I LOVE THIS!

I just read a couple of articles about user testing and I LOVE the idea of the TESLA (Time Elapsed Since Lab Attended) as a measure of how customer-centric your organization is. I still have to think about how practical it is to implement and what a realistic target could/should be for my executive team, but what a fantastically simple metric for a customer-centric software company to use.