I wouldn't advertise strictly as BBW either. Clients will have different ideas about what constitutes a plus size (unless maybe you're very short in height? Its pretty dependent to be honest) but yea in general 16 or 18 plus. Either way it doesn't matter where you work, it matters more where you advertise. If you are a BBW/SSBW you'll probably not want to rely on AW because you need a broad advertising brush stroke to attract those who are very very into larger women. Because its a niche they are smaller in number but so to are service providers so its relative - big fishes/small ponds etc - as I say you just want to look into BBW directories for example.
I'm a 14 (and reasonably tall) so in most places I advertise as curvy/hourglass/busty etc but I do advertise on some BBW directories because I do still attract some who like larger women specifically too , being in that limbo 'borderline' place of not-quite-plus size. (Although to some punters anyone over a dress size 8 is a plus size, lol). So yea as others have said its more about advertising rather than location, as I don't imagine there is a particular spot where men who like the big girls congregate in residence, especially
