The worldwide coverage of the Global Greening project, which sees famous buildings and landmarks around the world lit up in green for St Patrick's Day, is worth around €10m in advertising but cost less than €50,000, according to Tourism Ireland.
Figures released to RTÉ's Your Politics podcast show the total cost of running the scheme is €48,583 for St Patrick's weekend 2019.
The project has been running for the last ten years. It now sees sites such as the Empire State Building in New York, the Colosseum in Rome and Niagara Falls lit up in green on St Patrick's Day.
Tourism Ireland says that last year it conservatively estimated that the international media coverage was worth in the region of €10m, if it was to buy the advertising space in broadcast, print, and online media.
The project now has 470 sites participating in 55 countries across the globe.
The CEO of Tourism Ireland Niall Gibbons said the success of the project "is due in no small part" to the effort of the Irish diaspora around the world, and the support of the Irish embassy network.
He said: "Saturation coverage of the island of Ireland across the airwaves, in newspapers, and digital media is an invaluable boost at this time of year for our overall tourism marketing drive for 2019.
"The eagerness of cities and countries everywhere to take part underlines the strength of the deep connection that people all over the world feel to Ireland.
"More than 70m people around the world claim links to the island of Ireland and St Patrick's Day is a truly unique opportunity to reconnect them with their heritage."
This week on Your Politics podcast the RTÉ politics team discuss the latest developments on Brexit, the Government's plans for a new gambling regulator and suspension of Hungarian party Fidesz from the European People's Party group following attacks on European Commission President Jean-Claude Juncker.