Half of What Online Advertisers Know About You Is Wrong

Considering that they’ve never explicitly asked us about our preferences, it’s a minor miracle of big data that web advertising companies know anything about us at all. But at least half of the things they think they know about you—from your political preferences to your affinity for ladies’ fashion—could be wrong, and sometimes hilariously so.

Or at least, that’s what data from a survey put out by a firm called Enliken would suggest. Because Enliken’s business is getting people to give up more-accurate data about themselves in exchange for access to content. Because the survey wasn’t very big—covering just 116 people and about 9,000 data points—I took the survey myself in order to see whether ad targeting firms’ notions about my preferences were as inaccurate as Enliken suggested.