Using this technique, changes in the velocity of the star that is, the wobble caused by the previously unseen planet can be measured extremely accurately.

ECONOMIST: Is there anybody out there?

There's no reason, he says, that radio can't at least be as accurately measured as television, which once used the same methodology but eventually switched to electronic measurement.

FORBES: A Seismic Shift In Rating Radio

Such consumers can be targeted by internet advertisers and, in some cases, their responses accurately measured.

ECONOMIST: The future of advertising