THE GAA made €66m from Croke Park while it was used for massive events like concerts and Irish football and rugby matches.
The use of the venue to stage high-profile events provided a massive financial gain for the company that runs the stadium and, in turn, the GAA.
But the decision by Dublin City Council not to grant a license for Garth Brooks's five gigs this month, and the country star's decision to pull out entirely, could be a massive blow for the organisations.
An investigation by the Herald has found that as revenues generated from hiring out the facilities declined in recent years, so has the amount of money passed from Croke Park to the GAA.
This newspaper has obtained seven years of company records for Pairic An Chrocaigh Teornata and its subsidiary companies.
The accounts show that at its height in 2009 Croke Park gave €17m to the GAA Ard Chomhairle, the organisation's central council.
This followed a bumper year for the stadium when it received almost €19m for the hire of its facilities for various events.
It was the year that the venue hosted three massive U2 concerts as part of the band's worldwide 360 tour, which was a massive hit.
To top it off, there was also a Take That concert at the stadium during the summer.
A total of six rugby matches and four soccer matches were also held at the stadium that year.
The sporting events included the Heineken Cup rugby semi-final, in which Leinster defeated Munster 25-6.
But in 2012 - the latest accounts available - just €4m went to the Ard Chomhairle from the company that runs the stadium, less than a quarter of the 2009 figure.
That year, a single Red Hot Chili Peppers concert and two Westlife concerts were held at Croke Park.
The fees collected for hiring the stadium were €4.4m, also a massive drop when compared to 2009.
But the biggest year-on-year drop came between 2009 and 2010.
In 2010, the hire fees for use of the stadium were €7.1m, while €7m went from Croke Park to the GAA in the period. Both figures were less than half the previous year.
There were no concerts or international sporting events held at Croke Park in 2013, though accounts for that year are not yet available.
One Direction (above) played three gigs earlier this summer at the Dublin home of the GAA.
A spokesperson for Croke Park refused to reveal how much it charges for the hire of the venue, citing reasons of commercial sensitivity.
"We don't comment on the commercial arrangements with third parties for obvious reasons," a spokesperson told the Herald.
However, it is understood that the sum to hire the stadium for such events is over €1m.
As the number of lucrative events held at Croke Park has declined so, too, has the amount raked in by the GAA, so the Brooks decision is set to be a major blow.
It is likely that Croke Park would have made more than €5m if the country star's five-night extravaganza had gone ahead.
Since 2006, the figure paid to the GAA from Croke Park has always been similar to the funds the stadium received for hiring out its facilities for events such as concerts.