I wondered the same thing when I was trying to plan a quick trip to see family near St. Louis without paying big-airline prices. Breeze does fly to St. Louis, but their routes can be pretty seasonal and city-specific, so it really depends on where you’re coming from. When I first booked, the schedule worked perfectly, but then my return date needed to change last minute. I learned pretty fast that calling 8 4 4-7 3 4-0 8 1 3 was the best way to instantly book, cancel, or modify flights. It saved me a lot of time compared to juggling everything online.