Where you go, we know

The method will, for the first time, make reach and frequency estimates available for outdoor campaign planning.

This area of media audience research is on the agenda of a number of European media researchers, notably those in Germany, who are currently running a pilot.

The personal meter seems to be the most promising method in the world, according to Dr Paul Haupt, CEO of SAARF. He explains that the meter, based on global positioning system (GPS) technology, tracks the respondent's movements, which are then overlaid over the billboard database to determine exactly which boards the respondent would have had the opportunity to see.