From EightTwenty.ie, the people who compiled the handy Twitter Irish usage infographic.

They write:

What is surprising is the gap between the percentage of users in Dublin and outside of Dublin. The difference stands at 25% between the capital and second placed Limerick. In our Twitter study Limerick was 21st for the volume of tweets originating from the county, which either indicates there’s a great deal of inactive Twitter users in Limerick or they prefer Facebook to carry out their social networking activities.

Louth and Waterford appear near the top of this and the Twitter study. This would suggest the two counties are highly savvy when it comes to social media given that a high percentage of the local population are active on Facebook and send a high volume of tweets in comparison to other counties. In the same Twitter study we also noted the high volume of tweets, per thousand of the population, coming from Meath but the county ranks 20th out of the 26 counties with just 26% of the local population on Facebook.

In 14 of the counties we found just 1 in 3 people or less use Facebook, this is a significant difference to the number of Dublin users and from the national average in other studies. Making up the bottom two counties are Leitrim and Roscommon with just 19% of the local population using Facebook.

Facebook Users in Ireland by County (EightTwenty)