In 1998, two graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub", a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.[22] PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random web surfer.

Great SEO is increasingly dependent on having a website with a great user experience. To make your user experience great requires carefully tracking what people do so that you always know where to improve. But what do you track? In this 15-minute talk, I’ll cover three effective and advanced ways to use event tracking in Google Analytics to understand a website's user.
SEO may generate an adequate return on investment. However, search engines are not paid for organic search traffic, their algorithms change, and there are no guarantees of continued referrals. Due to this lack of guarantees and certainty, a business that relies heavily on search engine traffic can suffer major losses if the search engines stop sending visitors.[61] Search engines can change their algorithms, impacting a website's placement, possibly resulting in a serious loss of traffic. According to Google's CEO, Eric Schmidt, in 2010, Google made over 500 algorithm changes – almost 1.5 per day.[62] It is considered a wise business practice for website operators to liberate themselves from dependence on search engine traffic.[63] In addition to accessibility in terms of web crawlers (addressed above), user web accessibility has become increasingly important for SEO.
"Organic search" pertains to how vistors arrive at a website from running a search query (most notably Google, who has 90 percent of the search market according to StatCounter. Whatever your products or services are, appearing as close to the top of search results for your specific business has become a critical objective for most businesses. Google continously refines, and to the chagrin of search engine optimization (SEO) managers, revises its search algorithms. They employ new techniques and technologies including artificial intelligence (AI) to weed out low value, poorly created pages. This brings about monumental challenges in maintaining an effective SEO strategy and good search results. We've looked at the best tools to ket you optimize your website's placement within search rankings.

Optimizing a website may involve editing its content, adding content, and modifying HTML and associated coding to both increase its relevance to specific keywords and remove barriers to the indexing activities of search engines like Google ,Yahoo etc.[citation needed] Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.[3]