The link popularity of a site or page is calculated by counting the number of inbound links that site or page has. Google and other search engines rely fairly heavily on link popularity when deciding which pages are relevant to rank for certain search terms. Unfortunately for marketers the search engines have moved beyond simply counting the links when determining a site’s link popularity.
Instead a great deal of importance is placed on the quality of the site on which the link is placed. Whilst it cannot be known for certain the value a link will provide in terms of link popularity it can be reasonably assumed that a link from a high ranking authority site is worth considerably more than a link in the one thousandth comment at the bottom of a low quality blog.