I have been on a few such flights. Usually airlines use this more for marketing reasons than for generating revenue operating short domestic hops.
Although once it was a full 757 which offered a VNO-BUD for ~60 eur return. I think the charter airline (now defunct Aurela) managed to sell out the plane because there were no direct flights VNO-BUD and the timings were very convienient for a weekend trip. Still I am not sure they made money by selling those tickets instead of just simply positioning the plane for that charter order.