For the last decade, the internet has emerged itself into an integral part of our everyday life. What previously was a new network of research institutions happens to be an unprecedented medium for business and social use. With the amount of web pages now exceeding 12 billion, it is very difficult to find information without using search engines. You can easily find seo link building services and tips on the internet.
In their infancy, search engines were utterly at risk of abuse. Originally search engines accustomed to index file names and after meta-tags. To gain high rankings browsing engines webmasters used to goods file names and meta-tags with popular keywords that are irrelevant to the document's written content. When a user queried a search engine with a keyword he acquired results that couldn't satisfy your pet. That is why Internet directories with pages classified into directories by human reviewers were far more useful than search engines like Google of those days.
The problem of relevancy happens to be increasingly important with the growing commercial utilization of the Web. The profits of commercial websites be determined by their exposure and if you find anything that can help enhance the exposure in search results – it need to be done. So the first attempts to influence the listings by using popular but not relevant keywords to push more traffic were made.