Update your site's content often (at least show it's been reviewed recently).
Updating Your Site Often
Sometimes this is just not easy to do all the time, and so we have a tip that we are using on this page. The date shown above is always current. It is a javascript program that always displays the current date and so the page that it is on seems to have a current updated relevance. Besides this, it is always a good idea to update your site so that you avoid any outdated content. Search engines like Google love updates and changes on sites and give you more relevance points when your site is updated.
People give more credibility to web sites that seem to be updated or reviewed often.