Don't know if this will help anyone, but it seemed like a good deal if you can use it?
Virgin Atlantic have, as do most of the others, an Airmiles/reward points scheme. You fly with Virgin, earn "airmiles/reward points" with virgin and can then spend them on more flights or other stuff.
They have for a while now been doing a 20% off reward seat prices, but just had a look today and they are offering 50% off the normal reward prices (only seems to apply to economy seats). Little blue box at the bottom of the homepage.
Just as an example;
London to Orlando is around the £600 mark on the website for departures in the next 2-3 weeks including taxes.
London to Orlando with reward points is now only 25,000 instead of the usual 50,000, but you would still incur the taxes on this at around £130.
Obvioulsy not much good if you don't have any of the affore mentioned reward points, but somebody must have them!
You can also purchase reward points if you are a few short, which could still work out cheaper than booking a flight without them, if you see what I mean?
This won't be of use to everyone, but it might help someone. Hope it does.