First it was pretzels. Then it was the second checked bag. Then the first checked bag. Airlines continue to find creative ways to tack on extra fees to their advertised fares.

Now American Airlines said it will begin charging a fee, ranging from $19 to $39, for passengers who reserve one of the seats in the front of the coach cabin.

Calling the new fee program "Express Seats," American said the new fees for what was once free is now part of the "Your Choice line of products and services that provide customers a way to purchase special services they value."

Under the program, passengers must pay extra if they want to sit in the first few rows of coach, including bulkhead seats in that cabin. Additionally, customers who purchase an express seat will be allowed to board with Group 1 of general boarding for their flight. The airline says that will allow them to be the first coach customers on and off the plane.

Express sats are available to all American Airlines customers and can be purchased exclusively via airport Self-Service Check-In machines anytime from 24 hours to 50 minutes prior to scheduled flight departure for travel wholly within the United States, including Puerto Rico and the U.S. Virgin Islands.

Sliding fee scale

Introductory pricing for epress sats begins at $19 per flight, with pricing based on distance. Here are some examples of introductory prices for sxpress sats on some typical American Airlines routes:

• $19 for St. Louis to Chicago O'Hare

• $29 for San Francisco to Dallas/Fort Worth

• $29 for Boston to Chicago O'Hare

• $39 for New York JFK to Los Angeles

• $39 for Chicago O'Hare to Honolulu

"Express seats highlights American's focus on offering customers what they value most," said Virasb Vahidi, chief commercial officer for American Airlines. "This is another great product under the Your Choice program that puts more travel choices in the customer's hands."

Multiplying fees

Airline fees have begun to multiply in recent years as carriers looked for ways to add revenue. It began when fuel prices rapidly escalated.

Air Tran currently charges extra to reserve a seat in coach. Continental allows customers who pay in advance to reserve a coach seat.

Why not simply raise fares to cover higher costs instead of tacking on fees? The airlines claim they are providing more options, so the budget-conscious traveler doesn't have to pay for things -- like bags -- if they don't plan on taking any luggage with them. However, it also allows airlines to keep their advertised fares lower than they would ordinarily be.

Meanwhile, American said it still provides travelers with the option to pre-reserve other seats in the coach cabin at no charge.