Before we actually dive in to several aspects of SEO its necessary that we must understand how search engines work and what is the main goals of search engines, what really search engines like Google, Yahoo and Bing trying to accomplish with having a search engine.
There are two primary goals which almost all the search engines in the world are trying to accomplish.
1. To provide the user with best results for their queries and enrich their user experience. Its quite obvious if you are not getting what you are searching for then you will eventually won’t like using that search engine anymore and you may try to shift to other search sources available, so like you are developing your site or blog to get more visitors search engines are also evolving to give its users the best search experience which will in turn get them more users for their search engines.
2. To get more advertisers as possible: Now search engines are not operating like they are doing some social service for you for free No! If it operates like then there is no sense in Microsoft spending millions if not billions of dollars in to rolling out their latest search engine Bing to compete against Google or their move to operate with Yahoo, search engines look to sell more advertising space that way they get more revenue and that’s the whole point in Google researching so much in how to give its users best results as possible and periodically updating their algorithm and in fact one the major income for Google comes from their Google adwords feature where webmasters can get an account with adwords and advertise their site on cost per click basis and when you do a search for in yahoo the first prominent results you get are for the sponsored sites and these site owners pay to yahoo to get their sites up in search results, same goes with Bing or any other search engines, one of the main goal is to convert the traffic they get in to money.