As previous posters have said, seat choice is subject to ticket type, with cheapest ticket holders usually "banned". However, look at the "small print", it always tells you that pre-allocated seats cannot be guaranteed!
I find it particularly irritating when, because of the "penalties applied on my "cheap" seat,
particularly the "non-refundable" one!, I am almost guaranteed to be travelling on that flight. Fully-flexible ticket holders however, can pre-allocate a seat, and then not turn up!
