Spirit Airlines charging for carry-on

(NBC) – The skies may be friendly, but they're not free anymore. Starting August first, low-cost carrier Spirit Airlines will charge up to $45 for carry-ons that don't fit under the seat.

"I think it's terrible," said passenger Ann O'Malley.

But Spirit says sales are up 50 percent since they announced the fee. They argue it's actually a good deal.

Most passengers will pay $30 to stuff a bag in the overhead bins, but the airline says fares are down $40.

"They're still paying a little less than they paid today. But if they decide not to carry on a bag and help make the boarding even faster for us, we give them a nice big discount on their ticket," said Spirit Airlines CEO Ben Baldonza. "We don't see who loses on this."

Some travelers say it makes sense.

"Their pricing is so low to begin with, that usually you come out ahead," said passenger Scott McNish.

So, might other airlines follow suit?

"It'll be a little tougher for them to get away with it, because their fees aren't honestly as low to begin with," said Erik Torkells of TripAdvisor.com

While Southwest Airlines brags its the only major airline where "bags fly free,"

The government says bag fees are bringing other airlines four times what they did when the fees first started.

The government doesn't regulate bag fees, but last fall it did fine spirit $375,000 for a slew of violations, including denying and shredding customer complaints.

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