I looked at Southwest flights out of GSP to up north. (Philly and Newark) The problem is they are kind of pricey but the worse part is they don't offer any non-stop flights. Therefore, it ends up taking close to 5 hours to reach your destination. Although I don't fly much, I'd like to see some direct flights to up north. It would be nice for Southwest to offer them. Allegiant is good to go to FL but I wish they'd start some flight to the smaller airports up north like Allentown, PA. Even if they didn't offer the smaller airports, maybe non-stop to Philly. Allegiant prices are unbeatable if you book early enough. Maybe there would be more competition with Southwest to offer better prices as well.
Anyhow, I still have no clue what the billboard means.