The points just build up and you can get them for spending on just about any credit card. The customers are not, however, very happy, reports USA Today.

At least one very frequent business traveler tells the paper she simply chooses the cheapest ticket now, even though she could theoretically earn big trips with her frequent airline, United. The restrictions have made the effort to get the freebies more than it’s worth, she says. Southwest has certainly had that impact on a lot of travelers around here who find it much easier and cheaper to book Southwest than chasing American or United.

The paper reports that frequent fliers are now a smaller percentage (only 6 percent) of fliers than they were in 2002, when 8 percent were getting a free ride. What has causes this is not exactly clear. It could be that there are more blackout days and the airlines make the points hard to use but it could also be that the number of paying passengers has risen since the dark days in the immediate aftermath of 9/11. It is certain that airlines value paying customers over customer loyalty.

But the points just keep piling up, which say airlines and some expert analysts, proves that people still love the programs. Much of that growth comes from tie-ins with non-airline businesses trying to build loyalty like credit card companies and retailers. And that all got going when the airlines were trying to rebuild their customer base.

But it’s also become a profit center. All those partners buy those miles at 2 cents a mile, which generated an additional $4 billion last year.

Program executives say that more flyers get the dates and cities they want than don’t but some of that has learned the hard way. Haven’t we all learned that you have to book early?