I've always had success with medium sized US airports. Airports like CLT, MCI, BUR, LGB, SAN, etc. All of the hyper competitive people fight for JFK routes and I'm just chilling with a monopoly at PBI and OKC.
Thanks for the response. I've settled on CLT as there's a ton of demand out of there from what I can see. I'll probably try to get some JFK routes for transatlantic stuff but CLT seems to have good enough demand there as well