People are very sensitive to website loading time and Google is very sensitive to what people are sensitive to. This means that you should pay close attention to you website loading because everybody else importnat to your site is paying attention. Matt Cutts says that Google will be placing more and more emphasis on site loading speed in terms of how it affects ranking.
Is Speed That important
Remember those old Flash websites a few years ago? They had the big animated graphic telling you to just hang on, because everything was loading. My typical response to that graphic was this thought. “Nothing is worth waiting that long for – I’m Bouncing Baby”. Several widely cited studies show that very small increases in load time can result in big drops in page visits and other measurements of visitor engagement. For example a 1 second delay can result in a 7% drop in sales. Gone are the days of waiting for anything and load speed changes in your site deserve at least as much attention as any other single factor contributing to conversions.
You can test your load speed with several tools online, but here is very useful Google tool that yields detailed suggestions.