What's your attention span the first time you see a webpage? Test yourself: click on a page you've never visited before. Count to 5 in your head. Seems like a long time, doesn't it? If nothing grabbed you in that first 5½ seconds (or even the first 2 or 3 seconds!) you probably would have been out of there. The extra half-second might seem odd, but we've found it proves to be the most effective possible timespan.