Kantar Media Virtualmeter for use by Kantar Media PanelistsKantar Media Virtualmeter 171 is an new version (not an update) of our extension dedicated to the measurement of online audiences within "panels" of registered users that have given their consent to be measured. It does not have any visible part (toolbar etc.)but merely registers the surfing behaviour of registered panelists and sends this to the measurement servers of Kantar Media.