Nielsen//NetRatings reported that MLB.com attracted 1.6 million unique visitors on April 3, baseball's opening day. MLB.com, the home of Major League Baseball on the web, saw weekly traffic growth of 25 percent in the week prior to opening day.

"Over the past three months, we've seen sports consumers repeatedly flocking online for major events. The Winter Olympics and March Madness generated tremendous traffic gains for their host sites," says Jon Gibs, senior director of media, Nielsen//NetRatings. "The open question, however, is if these sites can turn these additional event-oriented visitors into repeat visitors. While huge events are great for site branding, if those visitors do not return, sites are missing an opportunity to gain significant advertising revenue," he commented.

While combined home and work visitors grew at a week-over-week rate of 154 percent on opening day, work users alone rose 170 percent from the previous Monday.