Ever wonder why some sites take forever to load while others appear in a snap? Let alone the associated user experience. It’s just more fun browsing a site that loads fast. And since Google now rates Adsense weight by load times, it makes more sense than ever to ensure that our pages load as fast as possible.
Especially with high performance websites, page load times are of highest concern. Not only user experience is directly affected, but bandwidth and hardware costs are often directly related to it. Yahoo did a marvelous job researching the elements that affect page loads and in response created the utility yslow.