] On June 2, personal-video-recorder outfit TiVo (TIVO )
] unveiled an analytical tool that can tell advertisers,
] agencies, and networks not only how many people tune in
] for a show but whether they're watching the ads. Unlike a
] Nielsen rating, which relies on surveys filled out by
] viewers, TiVo's system tracks what a viewer records and
] tunes into, even when the channel is changed