Building quality backlinks involves more than simply getting other websites to link to your website. Search engines value individual links differently, based on relevance, authority, and timeliness. An inbound link from an established website with high traffic and similar content is deemed to have more value than a link from an unrelated website with little traffic. Timeliness is also important, as certain links will lose value over time. While specific strategies differ, building quality backlinks for any website should focus on gaining inbound links from websites with an eye towards relevance, authority, and timeliness; the same criteria used by search engines to rate links.
Relevance is an important aspect of search engine optimization (SEO) and building backlinks. In this regard, quality is typically more important than quantity. Although the number of inbound links to a particular website factor into the ranking search engines apply, the links with the highest value are those links from websites with similar or relevant content. For example, links between a sports news website and a sporting goods supplier would be considered more valuable than links between a sports news website and an online dating website.
Along with relevance, authority makes a big difference in the perceived quality of your backlinks. Authority is simply the search engine's estimated ranking of a particular website. Websites with high traffic and numerous inbound links are assumed by search engines to be more authoritative than a website with less traffic and fewer links. Incoming links are the method by which search engines determine the popularity of a website. With more inbound links, the search engines assume a website's content is of interest to a large audience and therefore assign it more authority than another website with fewer backlinks.
The point of building backlinks to your website is to gain higher ranking in search engines, which in turn brings more traffic. It is an ongoing process over the lifetime of a website. Website owners must continually add backlinks to maintain search engine ranking, known collectively as pagerank. Accordingly, timeliness must also be a focus of building backlinks. Older links already indexed by the search engines do not have as much value as newer links, which indicate to search engines that a particular page is still of relevant interest to readers.
Other factors and components, such as anchor text, also determine the quality of a particular backlink in the eyes of search engines. Anchor text, the words used to hyperlink to another page, must be relevant to the website to which it links. Linking to a sports news website, for example, should involve the use of words relative to the content on that page. To search engines, irrelevant anchor text is a strong indication of linkspam, backlinks used solely to increase pagerank without regard to context. Penalizing a website by dropping its rank is common when search engines view certain backlinks as linkspam.