The charge for Switch is 40p per sector. The new charges make it cheaper for single passengers but much more expensive for 2 or more. I have checked the charges of some other carriers. FlyBE charges £4 per booking for credit cards and £1 for debit cards. EasyJet & BMI Baby also charge £4 for credit cards but have no charge if using a debit card. BMI charge £3 for credit cards and again no charge for debit cards. Aer Lingus appear to charge £3 a booking made onmline irrespective of the means of payment.
How much Ryanair makes on this depends on the ratio of individual passengers to groups/families of 2 or more. I guess it will add some more to the coffers.