I dont also consider Liverpool, Bristol, or Newcastle to be 'Main airports' but easyJet have bases there.
However the destinations in which they fly to from all of the above plus Doncaster, are main, internationally aclaimed airports (AMS, BCN, PMI, PRG, FAO etc) not out of town tin huts like some other blue and yellow airlines may take their customers.
I still cant believe people are referring to DSA as a 'base'. It is NOT. 1xA319 nightstops, as do 2 LPL based crews. (1 for the early FAO/PRG, and 1 for the late AMS/BCN/PMI). They may stay 1 , 2 or 3 nights, depending on how it is rostered, finally returning to Liverpool at the end of the 'trip'.
For example, a crew may do LPL-FAO-DSA (nightstop) DSA-FAO-LPL.
Hope this clears it up once and for all.