Incentives were just one factor that helped convince Denver budget carrier Frontier Airlines to double its Raleigh-Durham International Airport presence, according to a top exec.

Daniel Shurz, chief commercial officer for Frontier, says the flights announced Tuesday are “probably it” for the carrier at RDU in 2017. “But assuming they perform well, we’ll look to continue to grow beyond that,” he says.

The carrier announced Tuesday it would be debuting RDU’s first nonstop flight service to…