Google Pagerank is an important factor when it comes down to making money on the net. In general, the higher your Pagerank, the higher your results will show up in Google which usually leads to more traffic.
One of the factors that influences Pagerank is the number of incoming links you have to your site. The problem is when you have incoming links like http://www.yourcoolsite.com and http://yourcoolsite.com. What happens over time is that both of these URL's develop Pagerank even though its the same site.
To remedy this situation, you need to implement a 301 permanent redirect when people are brought to your site without the "www" (ie http://yourcoolsite.com). If you are running Apache and have permissions to use .htaccess files, all you have to do is to create a file called ".htaccess" (dont forget the dot at the beginning of the file) and slap in the following (dont forget to change the domain name ;-) and then dump it in your root directory.
ErrorDocument 404 http://www.yourcoolsite.com
RewriteEngine on
Options +FollowSymlinks
RewriteBase /
RewriteCond %{HTTP_HOST} !^www\.yourcoolsite\.com [NC]
RewriteRule ^(.*) http://www.yourcoolsite.com/$1 [L,R=301]
This will let Google know that http://yourcoolsite.com has been permanently moved and Pagerank should start to accumulate on http://www.yourcoolsite.com.
You can try it out ;-)
I don't know how this can be achieved through html but if anybody knows, feel free to chip in.
