By 2004, search engines had incorporated a wide range of undisclosed factors in their ranking algorithms to reduce the impact of link manipulation. In June 2007, The New York Times' Saul Hansell stated Google ranks sites using more than 200 different signals. The leading search engines, Google, Bing, and Yahoo, do not disclose the algorithms they use to rank pages. Some SEO practitioners have studied different approaches to search engine optimization, and have shared their personal opinions. Patents related to search engines can provide information to better understand search engines. In 2005, Google began personalizing search results for each user. Depending on their history of previous searches, Google crafted results for logged in users.
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).
AdWords is recognized as a web-based advertising utensil since it adopts keywords which can deliver adverts explicitly to web users looking for information in respect to a certain product or service. It is flexible and provides customizable options like Ad Extensions, access to non-search sites, leveraging the display network to help increase brand awareness. The project hinges on cost per click (CPC) pricing where the maximum cost per day for the campaign can be chosen, thus the payment of the service only applies if the advert has been clicked. SEM companies have embarked on AdWords projects as a way to publicize their SEM and SEO services. One of the most successful approaches to the strategy of this project was to focus on making sure that PPC advertising funds were prudently invested. Moreover, SEM companies have described AdWords as a practical tool for increasing a consumer’s investment earnings on Internet advertising. The use of conversion tracking and Google Analytics tools was deemed to be practical for presenting to clients the performance of their canvas from click to conversion. AdWords project has enabled SEM companies to train their clients on the utensil and delivers better performance to the canvass. The assistance of AdWord canvass could contribute to the growth of web traffic for a number of its consumer’s websites, by as much as 250% in only nine months.
Traditional advertising techniques include print and television advertising. The Internet has already overtaken television as the largest advertising market. Web sites often include the banner or pop-up ads. Social networking sites don't always have ads. In exchange, products have entire pages and are able to interact with users. Television commercials often end with a spokesperson asking viewers to check out the product website for more information. While briefly popular, print ads included QR codes on them. These QR codes can be scanned by cell phones and computers, sending viewers to the product website. Advertising is beginning to move viewers from the traditional outlets to the electronic ones.
The world is mobile today. Most people are searching on Google using a mobile device. The desktop version of a site might be difficult to view and use on a mobile device. As a result, having a mobile ready site is critical to your online presence. In fact, starting in late 2016, Google has begun experiments to primarily use the mobile version of a site's content42 for ranking, parsing structured data, and generating snippets.
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.
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. 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.