Stats this week from survey/research company Sysomos show that worldwide Ireland has 0.5% of Twitter users which works out at being 17th on Twitter accounts.
In terms of being noisy, we come 15th in volume. That is, 0.60% of Tweets on Twitter come from Ireland. Iran shows up on this list though which is probably to do with people listing they are from Iran to help the “green revolution” over there.
Our internet penetration as a percentage of global internet penetration looks to be about 0.2%, so we’re punching above our weight! (source)