Performance Issues for Amazon.com

Amazon.com says it is experiencing "latencies" that are affecting the performance of its web site, the Internet's leading retail store. "We are currently experiencing an issue that is impacting customers' ability to place orders on the Amazon.com website as well as the display of item details," the company said on a forum for sellers. "We are working to correct the issue and will continue to provide updates until service has been restored."

UPDATE: And it's back. After about three hours of problems, the Amazon.com site is displaying properly as of about 3:55 p.m. Pacific time.

The outage reports are reinforced by a steady stream of complaints on Twitter from customers who are unable to access the site or complete transactions. Some requests are returning "Service Unavailable" messages.

The problems didn't appear to affect Amazon Web Services, the company's cloud computing business. The AWS Service Health Dashboard is showing no outages or problems as of about 4:45 pm Eastern.

What's the cost of downtime if Amazon is unable to process orders? In the first quarter of 2010 the company's North American revenue was $3.78 billion, which works out to about $1.75 million an hour. The impact of outages is likely somewhat less than that, as AWS remained up and running throughout. Amazon.com's first acknowledgement of the problems was at 12:47 p.m. Pacific, meaning the incident lasted about three hours.

The downtime is notable because major outages ont eh Amazon.com retail site are rare, as noted on Twitter by Jesse Robbins. "Amazon operates of the largest & most reliable websites in the world & even the best fail from time to time," Robbins wrote.