I would think Jet2 ARE making money, their flights carry a good load factor with a variety of fares, high and very low.
With 2 new aircraft for next summer, i would think the following are possibilities for new routes:
London LGW
Belfast BFS
Jersey
Venice
Munich
Murcia
Ibiza
Tenerife
Paris CDG/ORY
I would also think that Malaga will go twice daily.
How about basing a couple of aircraft at Humberside as a route of expansion? Local support already in place and with enough catchment area to support both markets.
Regards
Mike