The study is based on Keynote monitoring the technical performance of nine companies' Web sites over a month. Some experienced more than 19 hours of downtime during peak periods, while others performed poorly over dial-up connections, indicating that the sites were designed with high-speed Internet users in mind.

The study evaluated credit-card sites of American Express, Bank of America, Bank One, Capital One, Chase, Citibank, Discover, MBNA, and Providian. While Bank of America, Capital One, and MBNA were the best overall performers in site responsiveness and site reliability, none of the sites ranked well in all 10 performance categories, which are: average T1 response, response-time consistency, geographic uniformity, load handling, average DSL response, average dial response, technical page design, network connectivity, reliability, and outage hours.

"What surprised us most about the study is the lack of focus on dial-up users by the credit-card companies in comparison to other financial-services companies that we benchmarked to," says Ben Rushlo, manager of professional services at Keynote. About 43% of U.S. households still use dial-up, according to Keynote. The study found that dial-up users had to wait on an average of 35 seconds to download each page of a transaction on these credit-card sites, which results in a very frustrating customer experience, Rushlo says. Customers use credit-card Web sites for interactions such as checking balances and recent charges, or for changing addresses.

Better technical page design is key to improving site responsiveness, Rushlo says. IT managers can tune specific elements of the site to improve its performance, which, in return, will improve the customer experience.

Downtime also affected many of the sites studied, even during peak periods. Bank of America and MBNA were down less than three hours during the course of a month, while the worst sites reported more than 19 hours of downtime, according to Keynote. "If you're unreliable, you're going end up pushing people into other channels," Rushlo says. A site that's down on a regular basis ends up pushing a higher percentage of customers to call centers, which is a much more expensive way of servicing customers than the self-service sites, Rushlo says.

As result, only Bank of America and MBNA have shown to be close to 99% reliable. The average for all of the sites was about 97.5%. That's a lower average than expected for this industry, Rushlo says, and the worst sites had availability of just under 94%. That gap surprised Rushlo: "The Internet is not new, and you would think that there would be more maturity now, especially for some of these sites that are so dependent on the online channel."