On the 30th anniversary of frequent-flier programs, miles and user options have soared — but so has frustration.

With literally billions of miles chasing a scarcity of cheap seats — 25,000-point flights, the longtime industry minimum for a domestic coach seat — consumer complaints are rampant. Ever-changing fees, blackout dates and other restrictions are adding to the discontent.

...

Industry experts say any redemption — whether it’s a gift card for gasoline or two tickets to Hawaii – builds customer loyalty. But for consumers perhaps nothing is more precious — and appealing — than a free flight.

“I would never cash in my miles for golf clubs because I would get less than a penny a mile in value,” says Randy Peterson, a frequent-flyer guru who’s built up a cache of more than 17 million air miles.

...