Scotland was close to Ireland and travel expenses were less than to America or Canada. Many Irish people already had family living in Scotland, who could help them find a house and work.
Scotland had a shortage of workers and so many industries in Scotland recruited the Irish. Some companies even paid the workers travel expenses and their rent, such as the jute mills of Dundee.
Wages in Scotland were higher than those paid in Ireland. In some cases they could be six times higher. Employment was also more regular and so more money could be made.
In Glasgow and Dundee there was a surplus of housing available. The tenements where the Irish lived offered a higher standard of living compared to the hovels they had left behind in Ireland. Houses were often offered with the promise of employment.