Online shopping surged on Black Friday, and most major retail sites held up well under the burden of increased traffic, according to recent reports.

ComScore found that online spending rose 22%, to $531 million, compared to last year, while Thanksgiving Day spending online rose 29% to $272 million. The company found that shoppers have spent more than $9.3 billion since Nov. 1.

"The Friday after Thanksgiving is known for heavy spending in retail stores, but it's clear that consumers are increasingly turning to the Internet to make their holiday purchases," comScore chairman Gian Fulgoni said in a statement. "Online spending on Black Friday has historically represented an early indicator of how the rest of the season will shake out."

Fulgoni said that Black Friday's growth shows momentum and bodes well for the season. He said he expected Cyber Monday sales to top $700 million.

"While this would make it the heaviest online shopping day on record, we can expect to see even stronger days ahead as the 2007 shopping season progresses into December," he said.

Video games, consoles, and accessories held the top slot for hottest retail product category, with a rise of 134% compared to Black Friday last year. The Nintendo Wii, PlayStation 3, and game Halo 3 drove growth in that category, Fulgoni said.

The furniture, appliances, and equipment category rose 36%, while consumer electronics rose 21%.

Online sales of toys rose 9% this year compared to last, and comScore attributed the slower growth in that category to recent disclosures about several toys containing toxic materials.

WebSitePulse, an Orlando company that remotely monitors Web-based systems, applications, and e-business transactions, said the Sears.com Web site was completely closed for online shoppers on Black Friday.

The site displayed a message saying it was "temporarily experiencing high traffic volume." The message appeared soon after 9 a.m. and didn't disappear until about 4:30 p.m, according to WebSitePulse, which said the message returned for another 45 minutes beginning around 9 p.m.

"Kmart.com, which is also run by Sears Brands, had the same problems, at the same times, but apparently the traffic there was not so heavy, and WebSitePulse's monitoring agents were able to complete successfully some of the tests during the day," the monitoring company said.

Keynote Competitive Research monitors traffic hourly from 10 major U.S. cities. The company reported mixed results for online retailers.

"Our monitoring of retail site performance has shown a definite slow-down in site performance over the course of Black Friday for many leading sites," Shawn White, director of external operations for Keynote, said. "Almost a third of the 30 leading retail sites we monitor for our holiday shopping index experienced significant slow-downs that impacted the product search and check-out processes -- and presumably will impact online sales."