Search engines use complex mathematical algorithms to interpret which websites a user seeks. In this diagram, if each bubble represents a website, programs sometimes called spiders examine which sites link to which other sites, with arrows representing these links. Websites getting more inbound links, or stronger links, are presumed to be more important and what the user is searching for. In this example, since website B is the recipient of numerous inbound links, it ranks more highly in a web search. And the links "carry through", such that website C, even though it only has one inbound link, has an inbound link from a highly popular site (B) while site E does not. Note: Percentages are rounded.
In February 2011, Google announced the Panda update, which penalizes websites containing content duplicated from other websites and sources. Historically websites have copied content from one another and benefited in search engine rankings by engaging in this practice. However, Google implemented a new system which punishes sites whose content is not unique.[36] The 2012 Google Penguin attempted to penalize websites that used manipulative techniques to improve their rankings on the search engine.[37] Although Google Penguin has been presented as an algorithm aimed at fighting web spam, it really focuses on spammy links[38] by gauging the quality of the sites the links are coming from. The 2013 Google Hummingbird update featured an algorithm change designed to improve Google's natural language processing and semantic understanding of web pages. Hummingbird's language processing system falls under the newly recognized term of 'Conversational Search' where the system pays more attention to each word in the query in order to better match the pages to the meaning of the query rather than a few words [39]. With regards to the changes made to search engine optimization, for content publishers and writers, Hummingbird is intended to resolve issues by getting rid of irrelevant content and spam, allowing Google to produce high-quality content and rely on them to be 'trusted' authors.

You may not want certain pages of your site crawled because they might not be useful to users if found in a search engine's search results. If you do want to prevent search engines from crawling your pages, Google Search Console has a friendly robots.txt generator to help you create this file. Note that if your site uses subdomains and you wish to have certain pages not crawled on a particular subdomain, you'll have to create a separate robots.txt file for that subdomain. For more information on robots.txt, we suggest this Webmaster Help Center guide on using robots.txt files13.
Make it as easy as possible for users to go from general content to the more specific content they want on your site. Add navigation pages when it makes sense and effectively work these into your internal link structure. Make sure all of the pages on your site are reachable through links, and that they don't require an internal "search" functionality to be found. Link to related pages, where appropriate, to allow users to discover similar content.
Mix up your official tweets about specials, discounts, and news with fun, brand-building tweets . Be sure to retweet when a customer has something nice to say about you, and don’t forget to answer people’s questions when possible. Using Twitter as a social media marketing tool revolves around dialog and communication, so be sure to interact as much as possible to nurture and build your following.
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.
Social media marketing provides organizations with a way to connect with their customers. However, organizations must protect their information as well as closely watch comments and concerns on the social media they use. A flash poll done on 1225 IT executives from 33 countries revealed that social media mishaps caused organizations a combined $4.3 million in damages in 2010.[93] The top three social media incidents an organization faced during the previous year included employees sharing too much information in public forums, loss or exposure of confidential information, and increased exposure to litigation.[93] Due to the viral nature of the Internet, a mistake by a single employee has in some cases shown to result in devastating consequences for organizations. An example of a social media mishap includes designer Kenneth Cole's Twitter mishap in 2011. When Kenneth Cole tweeted, "Millions are in uproar in #Cairo. Rumor has they heard our new spring collection is now available online at [Kenneth Cole's website]".[94] This reference to the 2011 Egyptian revolution drew an objection from the public; it was widely objected to on the Internet.[94] Kenneth Cole realized his mistake shortly after and responded with a statement apologizing for the tweet.[95]
Since heading tags typically make text contained in them larger than normal text on the page, this is a visual cue to users that this text is important and could help them understand something about the type of content underneath the heading text. Multiple heading sizes used in order create a hierarchical structure for your content, making it easier for users to navigate through your document.
Search engine optimization consultants expanded their offerings to help businesses learn about and use the advertising opportunities offered by search engines, and new agencies focusing primarily upon marketing and advertising through search engines emerged. The term "search engine marketing" was popularized by Danny Sullivan in 2001[12] to cover the spectrum of activities involved in performing SEO, managing paid listings at the search engines, submitting sites to directories, and developing online marketing strategies for businesses, organizations, and individuals.
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.