What does NPS stand for here? (Why does the original article explain one other acronym but not this one? Good journalism dictates that the first time you use an acronym that it's just possible not everyone knows in a story, you always explain what it stands for.)

Meanwhile, what about complainers who mostly complain (validly, but perhaps a bit too loudly) about bonus promotions that don't work (or where the airline changes the terms without notice in mid-stream)? UA's Months of Miles comes to mind.

It's one thing when there are complainers who just complain about everything. It's another thing when the complaining is caused by something the airline is clearly doing wrong but either doesn't care or can't fix. (Another example would be all the complaining about the way Southwest was messing up in the early days of the RR 2.0 swithover last year, or the current example of all the ways that the UA/CO merger transition is not working so well.)

But how does the airline identify complainers, if they only complain anonymously (say, via FT handles), and never directly to the airline, and never directly in any forum where they can be easily identified?

Meanwhile, the typical non-FTer airline complaint ends in "I'll never fly this airline again". (I hear it all the time around me in airports when there's been a IRROP.) If those passengers would just fullfill that promise (no matter whether this airiline has the lowest fares for their trip the next time or not!), there's nothing more the airline needs to do!

But perhaps "complainer" needs to be clarified. If I tell people my attempt-at-objective opinion of one airline or another, and it comes out negative (because of the facts), is that a complaint? Or is it only a complaint if I "whine" about it?