They get a lot of their work work from OAPs who still think of the Irish as the hardworking navvy from the 50-60s who came across from Ireland in their 1000s to work on britains roads and building sites,
They originally knocked on doors offering to Tarmac drives cheap with a bit of asphalt they had left from a road construction job , they then moved onto fascias & soffits, now they do pressure washing.
But in the end (like bdcs says) they get the work because they have the bottle to knock on doors and ask for it