Same day booking

Ryanair passengers can now book tickets online for same day travel (previously, they had to go and buy it at the airport):
- booking possible up to 6 hours before SDT (scheduled departure time)
and, same as for all other bookings
- online check-in up to 4 hours before SDT
- boarding pass to be printed up to 40 min before SDT

http://www.ryanair.com/site/EN/news.php?yr=09&month=jul&story=gen-en-260709

is this supposed to be some kind of last minute sale? they could sell these tickets imho as cheap as possible, trying to have all the flights fully occupied, what do you think?

Well, it could be good idea on very frequent routes where there are plenty of pax onboard. Those flights has some sort of risk to go to the airport and not get a flight. But on some other it might create many "last minute" hunters who won't bring money for the company.
This offer could be good for new company who would like to promote themself to some wider audience. Ryanair is very recognized company and has created solid bunch of sale hunters. In my example, I haven't bought a ticket which is more expensive than €5 for 1,5 year long! If knew that it's almost not possible to not get a last minute ticket - believe me, this way I wouldn't buy any more expensive

Usually, the tickets sold on the last days before the flight are very expensive indeed. I don't think that the last minute online bookings will mean very cheap flights ! Moreover, quite a lot of flights are sold out long before.