Its actually very popular over here. I live in a town called Charleville in County Cork and there are about 3,400 people living here. A Brazilian person got murdered here a few years back and the news reported that there were 120 Brazilians living here. In total, there are about 300 foreigners living here from Lithuania, Brazil, Romanians, etc.
All of these people go to Lidl because its what they are used to at home. This is big reason why Lidl has been succesfull over here.
Lidl and Aldi are all around the world. And when you can find an Aldi, you'll probably find a Lidle not far from it.
The bosses of both stores are brothers, they got in a fight, so one of the two brothers started his own store: Lidl. Now every time an Aldi opens, a Lidl is on it's way, I've witnessed it over here myself.