3/16/2007

The priority tag is used to set the priority of this URL relative to other URLs on your site. This has no effect on the priority of your pages against other peoples web pages.

Valid values range from 0.0 to 1.0. The default value is 0.5.

Since this value is relative setting all pages to have a priority of 1.0 is next to useless. Try to set the 'priority' values higher for index pages and 'landing' pages with rich content