how do you go about gauging supply/demand for a midterm rental in a specific area? Other than furnished finder, what are good ways to find a tenant for a mid term rental?
I do mid-term in the Portland Oregon Metro area. You can also operate mid-term by using Airbnb, VRBO, and other sites and set a 30 day minimum stay. You can also post furnished rentals on Zillow.com's rental site.
To check out how much supply there is in your area, I would search as a user looking for a rental. You may see the same listing across multiple platforms (lots of us experienced folks advertise in more than just one spot).
To see how much demand there might be, FurnishedFinder has a stats page that shows you the number of booking inquiries, and the number of available renters advertised on their site. You should also click as a traveler and check how booked the calendars for your competitors are.
Other less traditional ways to find prospective tenants for mid-term rentals include: insurance housing, networking with hospitals (works for travel nurses, as well as families traveling in from out of the area for major procedures), networking with construction companies.