Speeding up websites is important — not just to site owners, but to all Internet users. Faster sites create happy users and shown in studies that when a site responds slowly, visitors spend less time there. But faster sites don't just improve user experience. Users place a lot of value in speed — that's why search engines have decided to take site speed into account in search rankings. They use a variety of sources to determine the speed of a site relative to other sites.
Search engines are encouraging webmasters to start looking at their sites' speeds — not only to improve ranking in search engines, but also to improve everyone's experience on the Internet.