I always thought that Luton was under utilised by the airlines and thus passengers. It proves that if the flights are available folk will fly from Luton. Remains to be seen to what detriment, the massive development will have on the popularity during 2017.
With passenger loads looking good to Newark, an additional B757 and a second daily service might be in order even though it is now more expensive for the Brits to fly £ vs $.