Social networking sites such as Facebook, Instagram, Twitter, MySpace etc. have all influenced the buzz of word of mouth marketing. In 1999, Misner said that word-of mouth marketing is, "the world's most effective, yet least understood marketing strategy" (Trusov, Bucklin, & Pauwels, 2009, p. 3). Through the influence of opinion leaders, the increased online "buzz" of "word-of-mouth" marketing that a product, service or companies are experiencing is due to the rise in use of social media and smartphones. Businesses and marketers have noticed that, "a persons behaviour is influenced by many small groups" (Kotler, Burton, Deans, Brown, & Armstrong, 2013, p. 189). These small groups rotate around social networking accounts that are run by influential people (opinion leaders or "thought leaders") who have followers of groups. The types of groups (followers) are called: reference groups (people who know each other either face-to-face or have an indirect influence on a persons attitude or behaviour); membership groups (a person has a direct influence on a person's attitude or behaviour); and aspirational groups (groups which an individual wishes to belong to).
Social media itself is a catch-all term for sites that may provide radically different social actions. For instance, Twitter is a social site designed to let people share short messages or “updates” with others. Facebook, in contrast is a full-blown social networking site that allows for sharing updates, photos, joining events and a variety of other activities.
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. The 2012 Google Penguin attempted to penalize websites that used manipulative techniques to improve their rankings on the search engine. Although Google Penguin has been presented as an algorithm aimed at fighting web spam, it really focuses on spammy links 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 . 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.
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.