Ryanair's new payment card wheeze is a remarkably bad deal for consumers - the only time it's likely to be worthwhile given the hassle involved is for a person booking approx 15 or more sectors per year with Ryanair. By sector one person doing an outbound and return counts as 2 sectors, while 3 people doing a one way counts as 3 sectors.
A family of four would have to do at least 2 round trips every year to think about this payment card.