Source: flickr, Cubbie_n_Vegas, via 

First there was Spirit Air (NYSE:SAVE), charging for everything from printing a boarding pass to getting a cup of water. Then there was Allegiant Airlines (NASDAQ:ALGT), forcing customers to pay for carry-on bags, pillows, and blankets.

Now, Republic Airways' (OTC:RJETQ) Frontier Air will be joining this infamous group that includes confusing and expensive add-on fees for customers.

Both Spirit and Allegiant are ultra-low-cost carriers, so these charges aren't anything new to seasoned travelers. But with an announcement this week, Frontier will become one of the first non-ultra-low-cost airlines to impose such fees.

In a press release, Frontier said that customers would be charged up to $100 for placing a carry-on in the overhead bin. That charge could be as low as $25 if it is paid online in advance, and will be waived entirely if your ticket is booked directly through the company's website: The company also announced that it would be charging $1.99 for coffee, tea, soda, and juice.

While there's nothing wrong with trying to beef up revenue -- especially in an industry with economics as unfavorable as airlines' --customers who aren't tuned in to Frontier's press releases will likely be more than a little upset with the change.

And even if you do follow company releases, I have to wonder how seriously one might take the company's reasoning. As stated: "Frontier's most loyal customers have made it very clear that finding overhead bin space for carry-on bags has become unacceptably difficult."

Come on, guys. Why not just say that you need the money? Don't insult our intelligence.

While shareholders in Allegiant and Spirit have enjoyed solid gains over the past two years, such moves demonstrate how difficult it is to turn a profit in the air, and how quickly we are approaching the race to the bottom when it comes to service.