Basketball, religion, euthanasia and celebrities were behind the biggest jumps in website traffic in March, an Internet research company said Friday.

CNN.com, MSNBC and news sites owned by Gannett, which publishes USA Today, benefited the most from people's interest in the legal battle over Terri Schiavo and the child-molestation trial of former pop start Michael Jackson, ComScore Networks said. Schiavo, who was in a persistent vegetative state for 15 years, died March 31 after her husband won a legal battle to let his wife die.

Among the top 50 web sites, in terms of traffic, News Corp. Online had the biggest gain in March from Feburary, as 16.7 million Americans turned to the site, primarily to view news and to get more information on the company's popular American Idol TV show.

The NCAA Basketball championships, known as March Madness, was behind big gains in traffic at Sportsline.com, ESPN.com and NCAA sites.

The death of Pope John Paul II drove an average 22 percent gain in traffic in March from February at sites falling into the religious category. Compared with March 2004, the category saw a 53 percent rise, which was helped by Easter falling in March instead of April.

"The increase in traffic on religious sites was interesting," ComScore analyst Graham Mudd said. "We expected it at the news sites, but weren't expecting people to go to religious websites for breaking information."

Besides religion, discovering family heritage was a big draw last month. Online genealogy sites saw an average 31 percent increase in traffic. Driving the category was Ancestry.com, which experienced a 38 percent increase by offering free trials and making effective use of banner advertising.

Cable TV advertisements on Jamster.com, the cellular phone ring-tone provider, drove a 159 percent increase in traffic in March from February at the Jamba site. Jamba, which has been popular in the United Kingdom and Europe, is gaining attention in the United States because of the popularity in ring tones and a big advertising push, ComScore said.

Among online advertisers, Advertising.com reached 78 percent of all Americans online to remain No. 1 for the 11th consecutive month, ComScore said. Fastclick ads attracted 5.7 million more people than in February to take the No. 2 spot, and Yahoo reached an additional 4.2 million people to become No. 3.

CNN.com and MSNBC went up seven and three spots among advertisers to numbers 50 and 22, respectively, due to increased traffic.

Sports sites comprised half of the top 10 gaining properties in March, with NCAA sites posting a 473 percent gain from February, Sportsline.com, 82 percent; and ESPN, 34 percent.

Among the top 50 sites in traffic, Gannett's 13 percent increase in traffic moved it up six spots to 26, and ESPN, which also was helped by the start of Major League Baseball, attracted 4.2 million more visitors in March than in February to move up 18 spots to 33.

The top five properties in traffic for the month, in order, were Yahoo, Time Warner Network, MSN-Microsoft, Google and EBay.