January 23, 1998
Networks sell advertising time based principally on their performance among key demographic groups, which vary based on the time of day. Ratings performance in these categories gives a rough indication of network revenues in the given time period, though profitability can vary based on programming costs and other factors. The ratings below are for prime-time programming for the week of Jan. 12. Data for early- morning, daytime, late-night and Saturday morning programming were not available.