An article in the Economist today remarks on the need to identify the biggest fans of your product and service and listen to what they have to say about it.
It's well worth a read, though I think missing the mark in some cases, IBM made a mint from the PC revolution started by Apple and enflamed by Microsoft, so the point made there is a bit of a stretch.
Still and all, it seems to me as if the way to treat your best customers has always been pretty clear: give them what they want and lots of it for less than other folks would have to pay. It's served us well in the technology consulting game and I can't imagine it would hurt in any other industry either.
Happy Wednesday.