[leroy_masochist]

In terms of gaining/maintaining a holistic understanding of a given market and the competitive opportunities within it, I fully agree with your point that understanding the needs of one's existing customers is necessary, but not remotely sufficient.

That broader context is outside the scope of the work I usually do, though -- I'm usually focusing much more specifically on understanding the strength of existing customer franchises.

Certainly, two customers who give 9-out-of-10 scores might have very different levels of satisfaction. Sometimes it's a 9 because "I love the product and the customer service is great but on principle perfection is impossible and I don't give 10s" and sometimes it's a 9 because "the product is pretty good and does everything we need, but our main sales rep is really hard to get ahold of". This is why, in practice, I find that more insight comes out of the "why not 10" questions than the pure NPS number.