Shuttle America, the original Dash 8 airline served Wilmington and trenton as an independent LCC. In thier US Airways Express Saab existence, they flew from Trenton NJ to Bedford MA and I think Pittsburgh only once a day or so. It was even a crew base for Shuttle America.
I've always wondered if some of these smaller outlying towns from big hubs could be served by helicopter. It seems like alot of people would happily board a helicopter in Philly Northeast, Trenton, Wilmington, Atlantic City, South Jersey etc to connect in Philly especially if there was free parking and a hassle free check in. I don't know hoe profitable passenger helicopters are but perhaps they would be better for true commuter service.