FR's debit card fee (excluding Visa Electron) was previously £1.20 per person per sector. Now that's rocketed to £4 ppps. That's an increase of 333.33%.
If I recall correctly its credit card fee was previously £3 ppps. Now that's increased to £4 ppps. That's an increase of 33.33%.
Dramatic increases.
We don't know how many passengers buy return tickets and how many buy one-way tickets, so the following will just be an illustration: £4 x 50m passengers = £200m. So it'll generate a minimum of £200m from this ancillary revenue source. Of course, some people - probably a tiny fraction - will pay by Visa Electron as that doesn't yet incur a charge, but I foresee that that will change.
Anyway, it brilliantly illustrates how ancillary revenue, particularly fee-for-service components, very often supplements ticket revenue, and just how fundamental ancillary revenue, taken collectively, very often is. And it brilliantly illustrates how aggressive FR is in pursuing profit from every possible source.