Upselling has become a major strategy for the airline industry.

Carriers grab your attention with a low fare but then try to sell you a roomier seat, early boarding privileges or a refundable ticket, among other extras.

A passenger rights group says Delta Air Lines has pushed the tactic to new levels by shaming travelers into buying expensive upgrades.

When you choose a basic economy fare on Delta’s website, the final page before you confirm the purchase now lists several restrictions you face if you buy the cheap ticket. It warns that you will be last to board and last to access overhead bin space. It says you will get no seat assignment, no refunds, no ticket changes, no early boarding and no standby travel changes.

Paul Hudson, president of flyersrights.org, a nonprofit passenger rights group, compared the tactic to a car dealer that pressures buyers into paying for multiple upgrades to a basic car model.

"If it works, other airlines will likely try to follow," he said.

Delta spokesman Anthony Black said the purpose of the website section was not to shame people, but "to make people aware of what they are buying."

Frontier replaces toll-free help line

Denver-based Frontier Airlines has replaced its toll-free customer service phone number with a regular toll-charge line.

The move mimics a 2013 decision by the ultralow-cost carrier Spirit Airlines to save money by passing on to customers the cost of the phone calls.

Frontier’s move is no surprise considering that the same investors who for years financed Spirit bought Frontier Airlines in 2013.

Florida-based Spirit is known for super-low fares with a long menu of passenger fees. Spirit also has the nation’s highest rate of consumer complaints.

Why would Frontier want to follow Spirit’s example?

It’s probably because Spirit reported a profit margin of 21 percent in the most recent quarterly earnings, more than twice the average margin for the entire industry last year.

Hugo Martin, Los Angeles Times