TiVo currently sells second-by-second subscriber viewing information of television programs and commercials. However, the new announcement is specific to TiVo customer demographic data including age, income, marital status and ethnicity. Before you get too panicked about the privacy thing, note that the program is is strictly voluntary and all data will remain anonymous:
TiVo recruited 20,000 households to opt-in to the viewership panel. Because these subscribers have opted in, TiVo can associate household data with the viewership data, and hence will be able to produce program and commercial viewership reports which can be looked at by aggregate demographic and behavioral audience groups. All data remain completely anonymous.