Oh and adding it into the fare!
If it were added into the fare. No one would notice. The public are almost oblivious to taxes these days. It's just go straight to the end of the website - total the fare and then decide of they are going. The banner €1.99 each way just lures them in. An invitation to treat is the term I beleive - however, as the money goes to the airport for their service collect it at the check-in and drive on. At least they get the money straight away and we as passengers surely have enough change from the session the night before!
Rant over.