Most escorts have a place where they host, and if they have roommates or simply can't host at the moment, they focus their early earnings to save money to get a place to host.
Considering most clients want discretion and some are married to men or women who don't know they hire, hosting or the ability to do it is a huge part of the business.
Answering @Jarrod_Uncut's question, we shouldn't assume ALL escorts host WHEREVER they go. For instance, I know an escort who visited friends in Reno, slept in their sofa and did a couple of outcalls around the free time he had while vacationing. Some escorts because of personal circumstances like being comfortable with life as it is, having roommates, etc. prefer not to do in calls but again they're certainly leaving money on the table....