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.

Smartphone - In this document, "mobile" or “mobile devices" refers to smartphones, such as devices running Android, iPhone, or Windows Phone. Mobile browsers are similar to desktop browsers in that they can render a broad set of the HTML5 specification, although their screen size is smaller and in almost all cases their default orientation is vertical.

We expect advertisements to be visible. However, you should not let the advertisements distract users or prevent them from consuming the site content. For example, advertisements, supplement contents, or interstitial pages (pages displayed before or after the content you are expecting) that make it difficult to use the website. Learn more about this topic.38
To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots (usually ). When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.[47]
An SEO technique is considered white hat if it conforms to the search engines' guidelines and involves no deception. As the search engine guidelines[18][19][52] are not written as a series of rules or commandments, this is an important distinction to note. White hat SEO is not just about following guidelines but is about ensuring that the content a search engine indexes and subsequently ranks is the same content a user will see. White hat advice is generally summed up as creating content for users, not for search engines, and then making that content easily accessible to the online "spider" algorithms, rather than attempting to trick the algorithm from its intended purpose. White hat SEO is in many ways similar to web development that promotes accessibility,[53] although the two are not identical.
Let’s say, for example, that you run a construction business that helps with home repairs after natural disasters and you want to advertise that service. The official term for the service is “fire restoration,” but keyword research may indicate that customers in your area search instead for “fire repair” or “repair fire damage to house.” By not optimizing for these two keywords, you’ll lose out on a lot of traffic and potential customers, even if “fire restoration” is technically more correct.
Blogging website Tumblr first launched ad products on May 29, 2012.[69] Rather than relying on simple banner ads, Tumblr requires advertisers to create a Tumblr blog so the content of those blogs can be featured on the site.[70] In one year, four native ad formats were created on web and mobile, and had more than 100 brands advertising on Tumblr with 500 cumulative sponsored posts.
In 2007, U.S. advertisers spent US $24.6 billion on search engine marketing.[3] In Q2 2015, Google (73.7%) and the Yahoo/Bing (26.3%) partnership accounted for almost 100% of U.S. search engine spend.[4] As of 2006, SEM was growing much faster than traditional advertising and even other channels of online marketing.[5] Managing search campaigns is either done directly with the SEM vendor or through an SEM tool provider. It may also be self-serve or through an advertising agency. As of October 2016, Google leads the global search engine market with a market share of 89.3%. Bing comes second with a market share of 4.36%, Yahoo comes third with a market share of 3.3%, and Chinese search engine Baidu is fourth globally with a share of about 0.68%.[6]
Black hat SEO attempts to improve rankings in ways that are disapproved of by the search engines, or involve deception. One black hat technique uses hidden text, either as text colored similar to the background, in an invisible div, or positioned off screen. Another method gives a different page depending on whether the page is being requested by a human visitor or a search engine, a technique known as cloaking. Another category sometimes used is grey hat SEO. This is in between black hat and white hat approaches, where the methods employed avoid the site being penalized but do not act in producing the best content for users. Grey hat SEO is entirely focused on improving search engine rankings.

Website owners recognized the value of a high ranking and visibility in search engine results,[6] creating an opportunity for both white hat and black hat SEO practitioners. According to industry analyst Danny Sullivan, the phrase "search engine optimization" probably came into use in 1997. Sullivan credits Bruce Clay as one of the first people to popularize the term.[7] On May 2, 2007,[8] Jason Gambert attempted to trademark the term SEO by convincing the Trademark Office in Arizona[9] that SEO is a "process" involving manipulation of keywords and not a "marketing service."