Link Popularity history
To gain a better understanding of link popularity it is useful to know why it became so crucial for search engine rankings. In the past a web page’s ranking was determined, amongst other factors, by the number of keyword occurences within ‘on-page’ elements i.e. in page text, META tags, title tag. When web developers learned that they could trick a search engine hidden wiki to return their web pages by cramming keywords into their pages the search engines had to get a bit smarter.
They were using ‘on-page’ elements to determine relevance so it was only natural that they would look to elements out of direct control of the web page creator i.e. ‘off-page’ elements. Search engines made the assumption that the greater the number of links from other sites pointing to a web site, the more popular the web site is and therefore a more quality resource. This worked nicely in theory but in practice it was also to be abused.
Web site owners figured out many ways to get links pointing to their web sites one example of which was through the use of link farms, pages the contained nothing more than a collection of links, Quantity of links was being abused so the search engines made use of the old saying “quality not quantity” and began to assign a quality factor to each of the links pointing to a web site. Now web sites that had a higher number of high quality links were looked upon favourably by the search engines. Building link popularity became a science in itself and today is still the most time-consuming and frustrating activity for a search engine optimizer.
Main classes of links
Note: In the following examples SiteA is our web site and SiteB is an outside site (i.e. a web site under a different domain name than SiteA).
Inbound links:
Inbound links to a web site are links that originate from an outside web site. An example would be a link on SiteB pointing into a page on SiteA.