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.

Search engine marketing (SEM) is a form of Internet marketing that involves the promotion of websites by increasing their visibility in search engine results pages (SERPs) primarily through paid advertising.[1] SEM may incorporate search engine optimization (SEO), which adjusts or rewrites website content and site architecture to achieve a higher ranking in search engine results pages to enhance pay per click (PPC) listings.[2]
For example, to implement PPC using Google AdWords, you'll bid against other companies in your industry to appear at the top of Google's search results for keywords associated with your business. Depending on the competitiveness of the keyword, this can be reasonably affordable, or extremely expensive, which is why it's a good idea to focus building your organic reach, too.
The code of ethics that is affiliated with traditional marketing can also be applied to social media. However, with social media being so personal and international, there is another list of complications and challenges that come along with being ethical online. With the invention of social media, the marketer no longer has to focus solely on the basic demographics and psychographics given from television and magazines, but now they can see what consumers like to hear from advertisers, how they engage online, and what their needs and wants are.[101] The general concept of being ethical while marking on social network sites is to be honest with the intentions of the campaign, avoid false advertising, be aware of user privacy conditions (which means not using consumers' private information for gain), respect the dignity of persons in the shared online community, and claim responsibility for any mistakes or mishaps that are results of your marketing campaign.[102] Most social network marketers use websites like Facebook and MySpace to try to drive traffic to another website.[103] While it is ethical to use social networking websites to spread a message to people who are genuinely interested, many people game the system with auto-friend adding programs and spam messages and bulletins. Social networking websites are becoming wise to these practices, however, and are effectively weeding out and banning offenders.
While most of the links to your site will be added gradually, as people discover your content through search or other ways and link to it, Google understands that you'd like to let others know about the hard work you've put into your content. Effectively promoting your new content will lead to faster discovery by those who are interested in the same subject. As with most points covered in this document, taking these recommendations to an extreme could actually harm the reputation of your site.
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.

Page and Brin founded Google in 1998.[23] Google attracted a loyal following among the growing number of Internet users, who liked its simple design.[24] Off-page factors (such as PageRank and hyperlink analysis) were considered as well as on-page factors (such as keyword frequency, meta tags, headings, links and site structure) to enable Google to avoid the kind of manipulation seen in search engines that only considered on-page factors for their rankings. Although PageRank was more difficult to game, webmasters had already developed link building tools and schemes to influence the Inktomi search engine, and these methods proved similarly applicable to gaming PageRank. Many sites focused on exchanging, buying, and selling links, often on a massive scale. Some of these schemes, or link farms, involved the creation of thousands of sites for the sole purpose of link spamming.[25]
SEM is the wider discipline that incorporates SEO. SEM includes both paid search results (using tools like Google Adwords or Bing Ads, formerly known as Microsoft adCenter) and organic search results (SEO). SEM uses paid advertising with AdWords or Bing Ads, pay per click (particularly beneficial for local providers as it enables potential consumers to contact a company directly with one click), article submissions, advertising and making sure SEO has been done. A keyword analysis is performed for both SEO and SEM, but not necessarily at the same time. SEM and SEO both need to be monitored and updated frequently to reflect evolving best practices.
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]
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.
SEO techniques can be classified into two broad categories: techniques that search engine companies recommend as part of good design ("white hat"), and those techniques of which search engines do not approve ("black hat"). The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO.[50] White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.[51]

Marketers target influential people on social media who are recognised as being opinion leaders and opinion-formers to send messages to their target audiences and amplify the impact of their message. A social media post by an opinion leader can have a much greater impact (via the forwarding of the post or "liking" of the post) than a social media post by a regular user. Marketers have come to the understanding that "consumers are more prone to believe in other individuals" who they trust (Sepp, Liljander, & Gummerus, 2011). OL's and OF's can also send their own messages about products and services they choose (Fill, Hughes, & De Francesco, 2013, p. 216). The reason the opinion leader or formers have such a strong following base is because their opinion is valued or trusted (Clement, Proppe, & Rott, 2007). They can review products and services for their followings, which can be positive or negative towards the brand. OL's and OF's are people who have a social status and because of their personality, beliefs, values etc. have the potential to influence other people (Kotler, Burton, Deans, Brown, & Armstrong, 2013, p. 189). They usually have a large number of followers otherwise known as their reference, membership or aspirational group (Kotler, Burton, Deans, Brown, & Armstrong, 2013, p. 189. By having an OL or OF support a brands product by posting a photo, video or written recommendation on a blog, the following may be influenced and because they trust the OL/OF a high chance of the brand selling more products or creating a following base. Having an OL/OF helps spread word of mouth talk amongst reference groups and/or memberships groups e.g. family, friends, work-friends etc. (Kotler, Burton, Deans, Brown, & Armstrong, 2013, p. 189).[81][82][83][84][84][84] The adjusted communication model shows the use of using opinion leaders and opinion formers. The sender/source gives the message to many, many OL's/OF's who pass the message on along with their personal opinion, the receiver (followers/groups) form their own opinion and send their personal message to their group (friends, family etc.) (Dahlen, Lange, & Smith, 2010, p. 39).[85]

Having a different description meta tag for each page helps both users and Google, especially in searches where users may bring up multiple pages on your domain (for example, searches using the site: operator). If your site has thousands or even millions of pages, hand-crafting description meta tags probably isn't feasible. In this case, you could automatically generate description meta tags based on each page's content.
On the other hand, marketers who employ digital inbound tactics use online content to attract their target customers onto their websites by providing assets that are helpful to them. One of the simplest yet most powerful inbound digital marketing assets is a blog, which allows your website to capitalize on the terms which your ideal customers are searching for.