Had I seen it last Monday (the BBC reported it on Thursday), I'd have linked to this Akamai press release, Akamai and JupiterResearch Identify '4 Seconds' as the New Threshold of Acceptability for Retail Web Page Response Times, in my previous posting, Web and speed:
Based on the feedback of 1,058 online shoppers that were surveyed during the first half of 2006, JupiterResearch offers the following analysis:
- The consequences for an online retailer whose site underperforms include diminished goodwill, negative brand perception, and, most important, significant loss in overall sales.
- Online shopper loyalty is contingent upon quick page loading, especially for high-spending shoppers and those with greater tenure.
- JupiterResearch recommends that retailers make every effort to keep page rendering to no longer than four seconds.
You can download the JupiterResearch, vendor-sponsored (Akamai) report as a pdf via this page (requires registration). On page 9:
When it comes to page rendering, retailers must consider how well the site must perform in order to minimize shopper dissatisfaction. Based on recent survey data, JupiterResearch recommends that retailers make every effort to keep page rendering to no longer than four seconds. Overall, 28 percent of online shoppers will not wait longer than four seconds for a Web site page to load before leaving. Broadband users are even less tolerant of slow rendering. A full one-third of online shoppers with a broadband connection are unwilling to wait more than four seconds (compared with 19 percent of online shoppers with a dial-up connection). Consumers who have already invested in a high-speed Internet connection do so with the expectation that pages will load quickly. And, based on current availability, pricing, and adoption rates, JupiterResearch expects broadband adoption to reach nearly 78 percent of online households (or 58 percent of all US households) by 2010. The prevalence of broadband-connected online shoppers will continue to grow, and retailers must meet their expectations accordingly.
According to Akamai's press release,
Close to half of the retailers on the Internet Retailer Top 500 list still experience site response times in excess of four seconds, demonstrating the need for site acceleration services.
(Akamai: 'the leading global service provider for accelerating content and business processes online'.)
Quite a gap between four seconds and the 'increments of 100 milliseconds' Greg Linden says Amazon was testing. For Marissa Mayer, half a second 'killed user satisfaction'.

