What's behind the Trump-linked data firm that claims to know you

New York

STANDING before political and business leaders in New York last autumn, Alexander Nix promised a revolution.

Many companies compete in the market for political microtargeting, using huge data sets and sophisticated software to identify and persuade voters. But Mr Nix's little-known firm, Cambridge Analytica, claimed to have developed something unique: "psychographic" profiles that could predict the personality and hidden political leanings of every American adult.