The ratings for her initial broadcast Tuesday were 86 percent above what CBS averaged on the same day last year, according to a preliminary measurement of the nation's 55 biggest markets by Nielsen Media Research.
CBS had a 9.1 rating and 17 share in those markets, compared to the 5.7 rating and 11 share for ABC's "World News" and 5.3 rating and 10 share for NBC's "Nightly News," Nielsen said. A ratings point represents 1,102,000 households, or 1 percent of the nation's estimated 110.2 million TV homes. The share is the percentage of in-use televisions tuned to a given show.
Typically, NBC leads in the Evening News ratings, with ABC second and CBS third. All the networks expected extra curious viewers to watch Couric's debut.
Couric seemed to siphon viewers most from her old network: NBC was down 23 percent from a year ago, while ABC was down 15 percent, Nielsen said. More complete ratings from the entire country were due later Wednesday.
"This exceeded our expectations," said David Poltrack, chief researcher at CBS.