Fernando, you ask why Conti gets preference over Easyjet, despite the latter apparently having the bigger share of business?
At GLA, the amount Continental gives to Servisair for ground/pax handling for one flight would fund a whole day of EZY flights.
I imagine it is a similar situation at other stations
That's why they get the check-in staff, the boarding staff, loading staff, etc. It seems you do get what you pay for!