My understanding is that Ryanair were entitled to the airport incentives for the Liverpool service but they did not receive any such incentives for Dublin, Stansted or Gatwick.
Neither did Easyjet for Gatwick as they went head to head with BMI Baby
They put on an extra Stansted after Easyjet launched Gatwick and then really upped the Ante by going head to head with them on Gatwick during the winter of 2005. Things came to a head in June 2006 when Ryanair put 3 Gatwicks a day in their Winter schedule for 06/07 and shortly afterwards Easy announced that they were leaving ORK SNN and NOC.