Its one of little known things which we got through the good friday agreement aka the peace process, Ireland has to be promoted as a whole and as such the Northern Ireland Tourist Board can not as part of that agreement promote Northern Ireland, outside of Northern Ireland. Bord Failte will promote tourism to Ireland both North & South, but neither can do their own, on their own. Hope that makes sense
Personally I think its a good advert, but it would have been money better spent for Ireland as a whole and not for a restricted audience, after all Liam Neeson is now a global brand.