Webprofil sought to produce detailed audience profiles for participating websites by dropping cookies on panellists’ computers, recording what sites they visited and tying that to demographic information the panellist had previously shared with the company.

Details of the service and how it worked were set out in a page on the TNS Gallup Forum website (since deleted but cached here). The firm said information about Webprofil was also included in the terms and conditions presented to new members and those updating their information.

However, in a statement posted to its website TNS Gallup said: “We have become aware that there are members of the Gallup Forum who feel poorly informed in relation to their participation in Gallup Forum surveys… We recognise that we have not been sufficiently clear in our communication.”

Webprofil, it said, “is now closed”.