There used to be something called The Circuit, a loose confederation of madams around the country that hosted traveling providers for up to a week at a time. If you were a regular "reader" of one of the top two gentlemen's magazines back in the 80s and 90s, you'd recognize some of the names. (And, in Houston, at least, the going rate then was about what you'd pay for several of today's highly thought-of Dallas providers!)
The Circuit offered is clients variety. By doing so, demand was higher than it otherwise would have been with the same collection of local talent, a win-win situation for clients and providers. It also afforded some women the opportunity to work in places where there was almost zero chance of them being recognized or found out.
Back in the days of the TSML, it was not uncommon for some of the ladies mentioned therein to go on the road for a week or weekend. They made new friends and, again, enjoyed higher demand for their services since they were fresh talent who wouldn't be around for long.
To some extent, the same rationales still apply. A girl with an ECCE or P411 presence probably doesn't have the same concerns about recognition, although that's a big reason you find girls from the other side of the Metroplex or the Red River dancing in clubs. And sometimes a girl wants a change of scenery, and takes a "working vacation." Not having been anywhere except work, Bucks and home in two years I wouldn't mind three days in a Residence in Shreveport.
But I think the main rationale is sill the same: A traveling provider is new to the area and there for a limited time. If her reputation preceeds her, she'll be in higher demand over the period of the visit than she would be at home.