Why online tracking is going offline and just keeps getting creepier

From the article:

But online marketers are increasingly seeking to track users offline, as well, by collecting data about people's offline habits—such as recent purchases, where you live, how many kids you have, and what kind of car you drive.

Tracking people using their real names—often called "onboarding"—is a hot trend in Silicon Valley. In 2012, ProPublica documented how political campaigns used onboarding to bombard voters with ads based on their party affiliation and donor history. Since then, Twitter and Facebook have both started offering onboarding services allowing advertisers to find their customers online.