I understand that this is a charter company and they are offering half off for a reason. I also know that many of these type of companies have not made it. (Some do though - Spirit is an example). Direct Air is going on two years and made it through the fuel crisis last year. They have expanded in the past year, and hopefully that was because they are doing OK. I hope it doesn't drag them down with their new routes.
We have used them successfully in the past and wish them the best too. I understand that there is always a chance that these small airlines might not make it. I booked going into it with my eyes open. If we all stopped booking just in case they do not make it, then we ca be sure that they do not.
This airline uses secondary airports where both landing fee's and fuel are much cheaper than in big cities. This helps keep their expenses down. They lease airplanes, thus avoiding long term debt.
One of their locations is 5 minutes from my house, so it is great for us if they continue to fly.
Back up plan - free tickets on Southwest that I can cancel. I much rather use the free tickets for an expensive route or last minute trip. I will pay the $48 ticket price with Direct Air, be home from the airport in 5 minutes, enjoy the service and the wonderful Virgin American planes with TV's that they lease.
We have had good experiences with this airline and hope that their business model continues to work. They do tweek schedules and seem to be on top of changing market conditions. Good luck to Direct Air. It gives many of us a nice option to fly with.