Some of them are for webcam girls (if you look at the ads closely, they'll list multiple cities) or websites, et al.
We're a transition city as well, on a major interstate between Dallas and KC, with an airport with hub connections.
Whys that matter? Tis the season to explore other markets since the Holidays may be tapping out your own local market in a larger city. So I imagine some of the travelling girls are just looking for traction wherever they can find it... and just jaunting around for the holidays.
I'd think the locals would explore deeper clientele relationships during a slower time (some do, and do it well) but we've had a spate of girls who aren't into client development as much as they are hitting and quitting wallets. Not everyone though
Happy fun times!