JetBlue jumped on the checked bag fee bandwagon June 30 when the carrier began charging $20 per checked bag for online check-in and $25 per checked bag for airport check-in.

The move, announced in November 2014, leaves Southwest Airlines as the only remaining U.S. airline to offer complimentary baggage check.

In an interesting observation, Marty St. George, executive vice president for commercial and planning, JetBlue, told Reuters, “Half of the customers don’t even check bags. In effect, what’s happening is the customers who aren’t checking bags are paying for the customers who do.”

Checked-bag fees are a hot-button issue for frequent business travelers whose priorities include the availability of overhead storage space. As fees have become the norm, business travelers find themselves competing for bin space with leisure travelers and families — passengers who previously would have opted for the convenience of checked bags — angling to avoid paying the ancillary fee.

To avoid the checked-bag fee, customers can purchase tickets at the carrier’s Blue Plus fare. Averaging about $15 more than the base ticket price, Blue Plus includes one complimentary checked bag and slightly reduced change/cancellation fees.