I knew of a gay guy who was advertising several flats on air bnb but also aw. He upped his rent by at least 25 a day on the aw advert. So sometimes they are advertised elsewhere, for checking reviews etc.
Another thing to take into consideration is if something bad happens, what will the landlord do.. Most likely not have your back. I was attacked in an apartment that I've been using on & off for a couple of years. It took over 8 hours for the "landlord" to call me back.