Social media often feeds into the discovery of new content such as news stories, and “discovery” is a search activity. Social media can also help build links that in turn support into SEO efforts. Many people also perform searches at social media sites to find social media content. Social connections may also impact the relevancy of some search results, either within a social media network or at a ‘mainstream’ search engine.
Optimization techniques are highly tuned to the dominant search engines in the target market. The search engines' market shares vary from market to market, as does competition. In 2003, Danny Sullivan stated that Google represented about 75% of all searches.[64] In markets outside the United States, Google's share is often larger, and Google remains the dominant search engine worldwide as of 2007.[65] As of 2006, Google had an 85–90% market share in Germany.[66] While there were hundreds of SEO firms in the US at that time, there were only about five in Germany.[66] As of June 2008, the market share of Google in the UK was close to 90% according to Hitwise.[67] That market share is achieved in a number of countries.
Webmasters and content providers began optimizing websites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters only needed to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed.[5] The process involves a search engine spider downloading a page and storing it on the search engine's own server. A second program, known as an indexer, extracts information about the page, such as the words it contains, where they are located, and any weight for specific words, as well as all links the page contains. All of this information is then placed into a scheduler for crawling at a later date.

The kind of content you create depends on your audience's needs at different stages in the buyer's journey. You should start by creating buyer personas (use these free templates, or try to identify what your audience's goals and challenges are in relation to your business. On a basic level, your online content should aim to help them meet these goals, and overcome their challenges.
Inbound marketing refers to a marketing methodology wherein you attract, engage, and delight customers at every stage of the buyer's journey. You can use every digital marketing tactic listed above, throughout an inbound marketing strategy, to create a customer experience that works with the customer, not against them. Here are some classic examples of inbound marketing versus traditional marketing: