Many US airlines used to collect fares inflight, certainly on the east coast (BOS-LGA-DCA) shuttle but others too.
Ryanair have said they will be able to routinely offer free seats and make a profit once they have seatback screens offering hotels, car-rental, pay TV; plus revenue from selling food, drink and other stuff from the trolleys; and yes, charging £50 per CV (which I don't have a major problem with, they would otherwise get thousands of CVs from PPL-ers or worse, and the £50 probably cuts out the crap so most applications are serious ones from pros - a valid filtering process which also brings in a few £££).