I had an AirBnB that we recently converted back to a long term rental. Every situation is different, but our experience was:
-AirBnB/nightly rental market is completely saturated. Everyone and their uncle (and us, a year ago) thinks they are going to get rich with AirBnB (many of them don't actually track expenses, either, so they think they're doing better than they are) and competition has driven prices way, way down (at least if you want to actually have the place rented 75% of the time).
-The work to clean and deal with inquiries is considerable. Even for just a single unit (our basement apartment) that is located in our own house, we probably spent 2-3 hours per turnover. You can of course hire that out, but reliable cleaners *who will come on an inconsistent schedule and short notice* are not as cheap as you might think. If you choose to do it yourself, it's really not fun to scrub toilets.
-There will be a lot of vacancy. Even if your place is in a hot spot, and in demand - you will end up with someone booking for a week, then the next guest leaving a 1 or 2 day gap on a Tuesday or something that nobody will want. And if you're not in a super hot spot, your demand will be seasonal (or worse). We had about 75% occupancy but that required very aggressive pricing sometimes.
-Stuff wears out fast. If you have a nice place, keeping it nice will require replacing 10-20% of your furniture/linens/etc a year, conservatively. Sheets get gross after a few dozen different people have gotten lipstick and hair and sweat on them. Toasters break. Couches start to look shabby. On and on.
We ended up making a profit, after all expenses (albeit paying ourselves zero for cleaning) of about $15000 for 2017. Not bad, but that required (at a minimum) hundreds of hours of labor. The unit now rents for $1300/mo and other than finding tenants and the usual anticipated appliance repairs and such, there is zero work involved.
If I was paying $250k for an AirBnB it would need to be renting for a fortune every night. That is crazy crazy expensive for an 800 square foot barn conversion!
-W