They have done more creative ones than this before.
One things they don’t mention is that while the flights maybe cheap, you are charged from every carry-on and checked bags. So unlike most airlines where carry-ons are free and Southwest where carry-ons and two check backs are free, Spirit gets you for everything.
Most people travel with at least 1 carry-on and most people have 1 carry-on and 1-2 check bags, so while the flights rates are cheap, you will be paying an extra $30-200 just for your luggage, don’t be fooled.