6 Million of 12 Million do not type www before the yourURL.com. Thanks to Chris Finke for his excellent research. Chris is a wordpress developer and data collector, and not surprisingly, Matt Mullenweb wrote a WordPress plugin to redirect blog traffic typed without the www. Matt’s solution is great for WordPress developers and admins.

If your website doesn’t support traffic with and without the www, there is even some debate about whether this can reduce SEO for your content.
Business people have tried to figure out why half their traffic doesn’t find them. The answer is to automatically support “naked domains” so that people end up at your website even if they do not type www before your domain name.
Missing your website goes undetected. Your marketing or sales effort gets dropped and no one knows. Why is this ignored? Because the user who doesn’t type www never gets to your website, and never gets into your google analytics. they are just a lost marketing and sales effort.