Originally Posted by tinkicker

Genuine question but are you sure they sum like that? I've always interpreted it as being (in this case) 3 club tickets available? As in for full price 3 are available but we'd sell all 3 at a bit of a discount ("c" class) or 1 at a bigger discount (D or R). SO if someone went online to buy 3 tickets they'd find them priced at the "C " bucket and if they bought them then all the numbers would be zero.

Originally Posted by timcjp

My understanding is that this is the tickets being sold at that particular time. So each time someone makes a purchase or cancels, then all of the available booking classes will be updated based on the airlines revenue algorithm which will factor in not only how many physical seats available on the plane, but how much overselling they wish to do based on chances of existing seats being cancelled etc. etc. Quite often you might see that WT+ gets oversold when CW seats are available as they will then put through some upgrades, or similarly oversell CW if there is First availability etc.

All in all, I think these numbers can be a useful indicator but they are really a 'point in time' indication as no one knows what is going to happen next... who might cancel, who might buy more seats, what the airline might oversell etc. etc.