Vested interests
Happy to accept Expressflight's over enthusiastic championing of SEN as a direct result of his former employment there and not because of any commercial interests he may now have.
Easyjets per seat profits are public knowledge. Their average cost of their airport utilisation is approx 26-27% of seat revenue. As the majority of their summer flights out of SEN have been discounted to attract the pax we know that either 1) Easyjet are operating out of SEN at a loss right now or 2) SEN are paying Easyjet to be there. As these are relocated units (not new units) why would Easyjet make a loss to be at SEN? The answer is, they aren't making a loss. SEN are making a loss to promote their airport.
It will be interesting to see what happens when Easyjet have to pay the going rate for a landing and handling. If the pax loads don't support the £2.50 per seat profit margin they will relocate the aircraft. However I have pointed out that until meaningful time has passed all this is pure speculation. Let the spotters ooh and aah for now, it keeps them happy and the rest of us can put a distant date in the diary for a "I told you so" discussion in a few years time.