Columnist Jeff Jarvis of the UK's Guardian publication quotes the editor of the Los Angeles Times saying that online ad revenue is now sufficient to cover entire editorial payroll costs, including both print and online. Jarvis calls it a "moment in history," and it is, if it is true. It gives hope to ailing daily metro papers. Nielsen Online data for September indicate that the LA Times electronic publication is fourth among U.S. daily newspapers behind the New York Times, Washington Post, and USA Today. The Union-Tribune is not among the top 30 in the Nielsen list. The U-T has just laid off 20 percent of its pressroom employees -- 20 workers, including seven journeymen and 7 apprentices. Gannett, the largest U.S. newspaper publisher, has implemented a program requiring most US. employees to take a week off without pay. The publication eMarketer estimates that U.S. newspaper ad revenue declined 16.4 percent last year to $37.9 billion. It will be down to $28.4 billion by 2012, says the publication.