Having read all the comments about the subsities this route now attracts its fair to say bravo to United Airlines, who played a commercial 'A' game.
It now costs the public purse over £5m per year to sustain this service. Reading the reported 'load factor' numbers mentioned above suggests there is no shortage of takers for seats either. I understand yield and this leads me to these conclusions. Either:
A) United played the game and knew a threat to pull the service would end this way thus increasing even further their profit; or
B) Its an admission by United that operating the B757 transatlantic services just doesn't make enough money to make them worthwhile. NCL has clearly suffered and other UK regional airports have done so in the past.
I'm very much in the A camp on this but if there is a hint of B being true, other airports need to start worrying. United are fast approaching a period whereby it will become upgauge or die. Once the B757 starts to be retired (early 2020's at this stage) they have no suitable aircraft to continue the 'thin' transatlantic routes.