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. In markets outside the United States, Google's share is often larger, and Google remains the dominant search engine worldwide as of 2007. As of 2006, Google had an 85–90% market share in Germany. While there were hundreds of SEO firms in the US at that time, there were only about five in Germany. As of June 2008, the market share of Google in the UK was close to 90% according to Hitwise. That market share is achieved in a number of countries.
Google's search engine marketing is one of the western world's marketing leaders, while its search engine marketing is its biggest source of profit. Google's search engine providers are clearly ahead of the Yahoo and Bing network. The display of unknown search results is free, while advertisers are willing to pay for each click of the ad in the sponsored search results.
Facebook had an estimated 144.27 million views in 2016, approximately 12.9 million per month. Despite this high volume of traffic, very little has been done to protect the millions of users who log on to Facebook and other social media platforms each month. President Barack Obama tried to work with the Federal Trade Commission (FTC) to attempt to regulate data mining. He proposed the Privacy Bill of Rights, which would protect the average user from having their private information downloaded and shared with third party companies. The proposed laws would give the consumer more control over what information companies can collect. President Obama was unable to pass most of these laws through congress, and it is unsure what President Trump will do with regards to social media marketing ethics.
Optimizing a website may involve editing its content, adding content, modifying HTML, and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. 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.