FR would love to drop DUB-BRS to 2 daily and that was the plan but then EI announced 3 daily service and FR readded the third daily service and its only staying because EI are operating it.
Ryanair reduced BRS-DUB to 16 a weekly (2x daily with a 3rd on Mon and Fri) in winter 2010/2011.
When EI announced a 3 x daily BRS-DUB for summer 2011, FR returned to 3 x daily (as Jamie pointed out).
Last winter EI reduced to 2 x daily and carried that over into the current summer.
Ryanair remained at 3 x daily for this summer but in May (there may have been other months as well) the afternoon rotation was non-operational on certain days of the week.
DUB was BRS's most popular route in 2011 with 323,000 passengers.
Are you saying, Jamie, that FR is staying at 3 x daily (nominally at least) simply because EI is on the route with them? If that is the case the assumption must be that FR is either losing money on a 3rd rotation or at least not making the money it wants. It could be seen as Ryanair putting itself in thrall to EI.