Link building is undoubtedly one of most important tasks for better ranking and traffic. The ranking of a website is directly proportional to the number of links to your website. However, any link coming to your site cannot improve your rankings as the quality of the website from which it is being linked matters. Links coming from a spam website cannot be counted as a vote. Some of the criteria with which a link is valued are global/local popularity, anchored text, the link neighborhood in which the link exist, freshness, social sharing etc. SEO Coventry – http://www.blackwolfseo.co.uk/ provides methods to analyze the search links.