Oprah Winfrey has apologized to the millions of fans whose efforts to log into the self-empowerment guru's widely hyped Webcast on Monday were thwarted by overwhelmed Internet servers.

"We deeply regret that some of our audience did not have an optimal viewing experience and apologize for any inconvenience this may have caused," officials at Oprah's Harpo Productions said in a statement Tuesday.

The Webcast featured Winfrey and Eckhart Tolle, whose new-age bestseller A New Earth, is the current Oprah Book Club selection.

Harpo said more than 500,000 viewers attempted to watch the event -- but most could only see the first few minutes. After that, many of the servers powering the Webcast crashed under throughput demands of 242 GBps.

In its mea culpa, Winfrey's production company said it "recognizes that interactive Internet broadcasting to a mass audience is still an emerging medium."

Oprah fans made no secret of their displeasure. "It was heartbreaking to have the screen freeze continuously and then finally stop with only an explanation that the network was experiencing technical difficulties," a fan named "Calenejd" wrote on Oprah.com's message board.

"The broadcast kept freezing and sputtering and only caught a word here and there," said "4sandrella."

The Webcast was to be the first of 10 live events with Winfrey and Tolle. An on-demand repeat was posted Tuesday for viewing on Oprah.com. It's also available as an iTunes download.

Oprah's snafu isn't the first time that overwhelming demand has crashed Internet servers. New York magazine's Web site went dark for a time last month after thousands of people attempted to view the publication's nude Lindsay Lohan photos online.

In 1999, a Webcast of the Victoria's Secret fashion show in New York City famously crashed, leaving millions of viewers frustrated.