Tickets.com was unavailable for much of the morning after ticket sales began at 10 a.m. PDT. Many Fans looking to buy tickets were either timed out from the site or received error messages.
"Welcome to the Giants Virtual Waiting Room," Tickets.com said in its error message. "We're sorry, the event you have requested is experiencing very high demand. As a result, all requests for seats cannot be served simultaneously.
"We appreciate your patience during this peak demand period."
Tickets.com spokeswoman Melissa Zukerman acknowledged the problems, but said that some fans were able to get through and buy tickets. She likened the Web site problems to fans trying to buy tickets over the phone to a popular concert and getting a busy signal.
"(Giants) fans were very anxious to get tickets," Zukerman said. "The bottom line is that the tickets were sold out."
The Giants qualified for the World Series by beating the St. Louis Cardinals in the National League Championship Series on Monday. The Giants will face off against the Anaheim Angels, who knocked off the Minnesota Twins in the American League Championship Series.
The Angels and Giants will play two games in Anaheim over the weekend before heading to San Francisco on Tuesday. The best-of-seven series will include up to three games at San Francisco's Pacific Bell Park.
The Giants had 14,000 seats available for the three possible games scheduled for Pacific Bell Park, said team spokeswoman Bertha Fajardo. But the team only allotted 3,500 tickets for online sales, Fajardo said. In contrast, the Giants reserved 7,000 tickets for in-person sales at their box office, she said.
"We wanted to give those fans who come out and stand in line a better opportunity to get seats," she said.
But demand online was high. Keynote Systems, which measures Web site performance, said that it was completely unable to access the Tickets.com site from any of its measurement computers around the nation between 10:45 a.m. and noon on Thursday, a company representative said.
"The fact that Keynote was unable to access the site for approximately an hour and a half strongly suggests that Tickets.com was experiencing significant performance degradation and was most likely entirely unavailable," the representative said.
The Giants' area of Tickets.com had 1.3 million page views between 10 a.m. and 11 a.m. PDT on Wednesday, Fajardo said. That's the highest demand ever for Tickets.com, surpassing the crush for seats to the Salt Lake City Olympics and major concerts, she said.