They've obviously done a lot of number crunching to come up with that one, no doubt in their favour, but in the face of BOLT competition.
At €69 they've already got 12.5% of €559 of fares, or 15% of €460 of fares whether you do them or not, and 12.5% of your remaining ac fares, and then appealing to drivers who might prefer there not to be a record of cash fares. The % of ac fares must now be very high, and no doubt will be "encouraged" more in the future by FN.