Brave New Word: Web Developers: Speed up your pages!: “There is a ton of research on user behavior based on task response time and I’m sure if you search Jakob Nielsen’s site you’ll find something.
I remember an IBM study made more than 15 years ago that said if it took 1 second for the computer to respond, it would take 1 second for the user to start the next step, but, if it takes 10 seconds for the computer to respond, it takes 20 seconds for the user to start the next step on his task. It is an exponential problem because users get more and more distract the longer it takes for a command to respond.
Web sites are no different. Google proved with its super fast pages (part real, part perception) that users will perform many more searches if they know they don’t have to wait long. If each query on Google would take 20 seconds to respond, you are more likely spending more time thinking about what search terms you’ll use. But since it takes just 3 seconds, you just keep adding and removing search terms.
So, during the past few weeks I’ve been collecting tips for Web Developers on how to improve their page speed. These tips effect latency, bandwidth, rendering and/or perception of when a page is ready. They are in no particular order.”