Nielsen Media Research could soon face further troubles over its controversial audience measurement system, this time stemming from a rival service.

Nielsen's Local People Meters, currently sweeping through US metropolises, are able to measure the time viewers spend watching a video-on-demand channel, but not what they choose to watch.

And this is just what might be on offer if cable TV companies such as Comcast and Cox Communications succeed in wooing media agencies with their plans.

Future services could provide demographic and geographic viewer data, although Cox Media's vp for marketing and new media, Debbie Mullen, says the delicate issue of consumer privacy is a "hurdle".

Such sophisticated systems are "the future of television" according to Starcom MediaVest Group's svp for emerging contacts, Tim Hanlon, who added that "this is Nielsen's game to own or lose."

Nielsen, meantime, remains coy about its future measurement services, revealing only that the systems would encode TV programmes and films to help tracking.

Earlier this year, the American Association of Advertising Agencies' Advanced Television Group committee asked cable firms for data to help define "gross universe counts", a typical stumbling block for media agencies.

Although its is predicted that 16.8 million homes will have access to VOD services this year and 31.1m by 2008, only just over a quarter currently access the available channels, according to Jupiter Research.

Comments Optimedia's Bob Flood "Technology may be available to people, but how many elect to use it?"

Data sourced from:; additional content by WARC staff