Mining for votes ahead of New Hampshire polls

When primary voters go to the polls on Tuesday in New Hampshire, most of them will do so knowing just as much about the candidate as the candidate knows about them. Past voting records, consumer data and internet behaviour have led to a revolution in the way political campaigns find and target voters.

Aristotle is one of those companies that collects data, down to the voters' hobbies, and sells it to campaigns, political organizations and government agencies.

Over 190 million American voters are on file, and Aristotle's clients currently include several Republican candidates and every US president since 1983. The data can help campaigns to find a specific voting block that may swing an election in their favour.

The BBC's Katty Kay went behind the scenes at Aristotle and talked to voters in New Hampshire about the tailored campaign messages they were receiving.

Produced by the BBC's Franz Strasser.