Panel members have been equipped with modified mobile phones which record exposure to TV advertising through sound recognition. Recorded data is sent back via the phone’s network and GfK then uses statistical transmission information from Thomson Media Control to determine which programme the respondent was watching when they were exposed to the advert.

“This enables precise determination of which advertising campaign a particular panel participant viewed at what time,” said GfK in a statement. And because WEP panel members also record their retail purchases, the company should be able to measure which advert exposures generate the most impact on buying behaviour.

GfK says it is currently monitoring ad campaigns on Germany’s 11 largest commercial TV stations, accounting for more than 90% of TV advertising revenue. The WEP panel, meanwhile, comprises 20,000 individuals within 10,000 homes.

A UK version of the panel was launched in November last year, called the Media Efficiency Panel – covering both online and offline media consumption.