easyJet have been attracting business passengers on many routes for ages, mainly due to some of the following reasons:
a) They are the only airline operating a particular route;
b) Business passengers like low prices too; and
c) Instead of a 'legacy carrier' flexible business class ticket you can just book a 'loco' cheap seat on two or three flights around the day/time you might need to travel.
I travel extensively within Europe and have flown easyJet numerous times for reasons a) and b). At morning and evening peaks, flights I've been on have often been full of 'suits'. I'd not consider doing c), as it's a bit cheeky and greedy, but I know people who have. The new easyJet £99 flexible business fare is probably meant to address that.
In these times of austerity, I think businesses that keep their costs down where they can, are better regarded. What I have done in the past is travel out loco (as my meeting start time/date is fixed) and back legacy business (where the finish time is unknown); that's worked well. Will people use the new £99 service? easyJet are gambling they will. As they say, time will tell.