Ryanair is possibly the world’s most successful  cheap flights airline. Offering a no-frills service, they promise to get their customers from A to B with the minimum of fuss and at the cheapest possible cost. To this end, seats on Ryanair are sold cheaply, but everything else is extra.  You have to pay for luggage, and for checking in. Failure to do so online, means paying through the nose at the airport. You cannot book a Ryanair plane except online. To save costs they have closed offices. Less overheads means cheaper flights. Ryanair Cheap Flights