Jones also provides tips and tricks to manage SEO projects. "You should be aware by now that the number and quality of external links that come to your site are an important factor in achieving good rankings," he writes "You need to be able to see how many URLs have links to your site and their quality, which is measured by its PageRank. A PageRank of 10 is the highest and rarest. You're looking for PR 3-4 and above."