Ryanair doesn't operate connecting flights, and they sell very few flexible or refundable tickets. These are the main opportunities for people to not make thei

Ryanair doesn't operate connecting flights, and they sell very few flexible or refundable tickets. These are the main opportunities for people to not make their flights, and thus for overbooking to be attractive. A passenger not showing up is pure profit as Ryanair even gets to pocket the taxes, which are only payable on actually flying passengers (you can claim them back, but there's a substantial handling fee IIRC).