When technology executives talk about the allure of opening offices in Ireland, they typically refer to the country's wealth of talent and its proximity to European customers. Some even tout the pubs.
Less frequently mentioned, at least in press releases, is the most important factor: Taxes.
Apple was all over the headlines on Tuesday after the European Commission ordered the iPhone maker to pay 13 billion euros ($14.5 billion) in back taxes to Ireland. While Apple is the biggest tech name with the longest history in Ireland, having opened up shop there in 1980, many of Silicon Valley's most notable brands now call Ireland their European home.
Google, Facebook and LinkedIn established European headquarters in Dublin, and smaller companies like Zendesk, Dropbox, HubSpot, Slack and Glassdoor have set up Irish footholds. Salesforce.com said Ireland played a "key role" in its European success upon opening a second Dublin office in 2013.
Ireland does have highly regarded engineering programs at Trinity College Dublin and University College Dublin, and there's no question that the prominence of Guinness is a draw.
But the country has one distinct advantage over its neighbors to the east, north and south. Its corporate tax rate of 12.5 percent is the lowest in Western Europe and 10 percentage points below the average in the European Union, according to KPMG.
"At the end of the day, regardless of what companies are saying, it's the taxes that have to be paid that's the driving force," said Thomas Cooke, a professor at Georgetown University's McDonough School of Business. "It's the obligation of a company to do what's in the best interest of the corporation and its shareholders."