Oh, and my wife tells me that IATA rules restrict overbooking to 10% capacity. An airline can distribute that amongst the classes as they see fit. EK won't overbook F (LH I think is experimenting with that though), but they will push the legal limits.

But it works out. Last year I was waiting to board and loading agent came round asking if anyone would like to give up their seat in return for free return tickets to match their current itinerary. A third of the hands in the room shot up. Y travellers on holiday love those deals.