And while many retailers have been prepping their websites, building site capacity and testing load and performance up to 11 months prior to the holiday season, the Black Friday and Cyber Monday of the last week demonstrated that some had not prepared nearly enough.

Web monitoring firm Keynote (keynote.com) has been following the online activities of 30 leading retail sites, including Abercrombie & Fitch, Banana Republic, Gap, Macy's, Saks Fifth Avenue, Sears, Barnes & Noble, Target, Wal-Mart, Amazon.com, Best Buy, Toys R Us and Wal-Mart.

Keynote collected retail index data using its performance measurement and monitoring service, Transaction Perspective 8.0, and offered updates on the product search, shopping cart and check-out process performances. Not surprisingly, both Black Friday and Cyber Monday showed mixed results for the retail sites.

"We saw performance slow-downs, and in some cases, what would have appeared as outages to a customer, both on Black Friday and Cyber Monday," says Shawn White, director of external operations for Keynote. "about a third of the sites we've seen have some significant performance issue that would have frustrated anyone doing online purchasing on these days."
These slow-downs that impacted the product search and check-out processes in all likelihood had an effect on the retailers' sales, although Keynote itself does not measure sales figures.

The Web monitoring firm recorded slow-downs and some retail site problems beginning at 9:00 a.m. Eastern time on Friday, November 23. For many sites, the lasted through 10:00 p.m. - the peak Internet usage times when consumers from coast to coast are accessing retail Web sites. Monday November 26, Cyber Monday, saw similar performance issues as many consumers continued shopping from their homes or offices.

"We definitely saw some performance issues occur on Cyber Monday," says White. "It looks like with those sites that had problems, they generally started around 11:00 a.m., and were cleared up around 1 p.m. West coast shoppers are waking up in the morning while East coast shoppers are shopping from work during their lunch hour, and it clears up when the West coast online shoppers are finishing up on their lunch break and getting back to work."

A few sites suffered through significant slow-down periods, including BestBuy, which Keynote says slowed down several times during the day, and Toys R Us, which slowed down by almost 300 percent on Cyber Monday from 1 p.m. to 5 p.m. Despite the slowdowns, this year's performance was much improved over last holiday season when several leading sites experienced multiple temporary outages.

This year, both Sears.com and the Sears-owned Kmart.com were completely down for most of Black Friday, November 30, 200 displaying the message, "temporarily experiencing high traffic volume" on its front page from just after 9 a.m. to 4:30 p.m.

Ensuring performance in the holiday season is key for online retailers, says White. Site operators should ensure that they are properly load balancing their back-end systems. He suggests they consider vendors specializing in Web management services.

"What we recommend for our customers and the industry as a whole is to start load testing," says White. "Not just the home page and not just the site, but really load testing the entire end to end Web application from when a customer would go to the site to when they would purchase a product. It's all about preparing in advance, load testing, and continuing to measure yourself over time, even under normal circumstances so that you form a baseline of what your customers expectations are."