Upgrades and improvements to the site triggered three blackouts ranging in length from an hour to 90 minutes, spokeswoman Cynthia Lee said Monday.
The glitches come only a month after Wal-Mart, the nation's largest brick-and-mortar retailer, unveiled the overhauled site it took more than a month to complete. To perform the facelift, Walmart.com even shut the site down.
Analysts have warned e-commerce companies not to tax their customers' patience this season with site outages and slowdowns. Consumers expect more from Web merchants this season after so many fumbled last year at such basic tasks as shipping, processing transactions, and handling return merchandise.
This year, analysts said, consumers would quickly tire of technical glitches and slow sites.
Although no other brick-and-mortar retailer has more customers than Wal-Mart in the offline world, the online arm of the company has failed to build anything comparable on the Web. Traffic-tracking company Media Metrix estimated Walmart.com's traffic to barely be among the top 50 retail sites.
Walmart.com chief executive Jeanne Jackson said last month that she has laid out a plan for the site to become as consumer-friendly as possible.