Win Web Hosting

It’s been said that if it takes a user longer that 6 seconds for a web page to load that abandonement will occur at a higher rate than one which loads within 5 seconds and after 10 seconds users frustration jumps even more. You might want to look at studies such as the one on this page.
http://www.websiteoptimization.com/speed/1/

A good way to measure performance is using a company like keynote which will give you performance results. After that If you don’t like the results you see, you could do many different things depending on what your site does and how it’s generated. From local load balancing, to using a content delivery network like Akamai which will not only relieve the load off of your server it will also give you the ability to scale when your site goes through peak usage periods.