As of 2009, there are only a few large markets where Google is not the leading search engine. In most cases, when Google is not leading in a given market, it is lagging behind a local player. The most notable example markets are China, Japan, South Korea, Russia and the Czech Republic where respectively Baidu, Yahoo! Japan, Naver, Yandex and Seznam are market leaders.
Search engines may penalize sites they discover using black hat methods, either by reducing their rankings or eliminating their listings from their databases altogether. Such penalties can be applied either automatically by the search engines' algorithms, or by a manual site review. One example was the February 2006 Google removal of both BMW Germany and Ricoh Germany for use of deceptive practices.[54] Both companies, however, quickly apologized, fixed the offending pages, and were restored to Google's search engine results page.[55]
Often the line between pay per click advertising and paid inclusion is debatable. Some have lobbied for any paid listings to be labeled as an advertisement, while defenders insist they are not actually ads since the webmasters do not control the content of the listing, its ranking, or even whether it is shown to any users. Another advantage of paid inclusion is that it allows site owners to specify particular schedules for crawling pages. In the general case, one has no control as to when their page will be crawled or added to a search engine index. Paid inclusion proves to be particularly useful for cases where pages are dynamically generated and frequently modified.

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.

Social media can be a useful source of market information and a way to hear customer perspectives. Blogs, content communities, and forums are platforms where individuals share their reviews and recommendations of brands, products, and services. Businesses are able to tap and analyze the customer voices and feedback generated in social media for marketing purposes;[15] in this sense the social media is a relatively inexpensive source of market intelligence which can be used by marketers and managers to track and respond to consumer-identified problems and detect market opportunities. For example, the Internet erupted with videos and pictures of iPhone 6 "bend test" which showed that the coveted phone could be bent by hand pressure. The so-called "bend gate" controversy[16] created confusion amongst customers who had waited months for the launch of the latest rendition of the iPhone. However, Apple promptly issued a statement saying that the problem was extremely rare and that the company had taken several steps to make the mobile device's case stronger and robust. Unlike traditional market research methods such as surveys, focus groups, and data mining which are time-consuming and costly, and which take weeks or even months to analyze, marketers can use social media to obtain 'live' or "real time" information about consumer behavior and viewpoints on a company's brand or products. This can be useful in the highly dynamic, competitive, fast-paced and global marketplace of the 2010s.

In addition, social media platforms have become extremely aware of their users and collect information about their viewers to connect with them in various ways. Social-networking website Facebook Inc. is quietly working on a new advertising system that would let marketers target users with ads based on the massive amounts of information people reveal on the site about themselves.[104] This may be an unethical or ethical feature to some individuals. Some people may react negatively because they believe it is an invasion of privacy. On the other hand, some individuals may enjoy this feature because their social network recognizes their interests and sends them particular advertisements pertaining to those interests. Consumers like to network with people who have interests and desires that are similar to their own.[105] Individuals who agree to have their social media profile public, should be aware that advertisers have the ability to take information that interests them to be able to send them information and advertisements to boost their sales. Managers invest in social media to foster relationships and interact with customers.[106] This is an ethical way for managers to send messages about their advertisements and products to their consumers.
Reddit, or similar social media platforms such as Stumble Upon or Digg, are ideal for sharing compelling content. With over 2 billion page views a month, Reddit has incredible social media marketing potential, but marketers should be warned that only truly unique, interesting content will be welcomed. Posting on Reddit is playing with fire—submit spammy or overtly sales-focused content and your business could get berated by this extremely tech-savvy community.
Companies that employ overly aggressive techniques can get their client websites banned from the search results. In 2005, the Wall Street Journal reported on a company, Traffic Power, which allegedly used high-risk techniques and failed to disclose those risks to its clients.[15] Wired magazine reported that the same company sued blogger and SEO Aaron Wall for writing about the ban.[16] Google's Matt Cutts later confirmed that Google did in fact ban Traffic Power and some of its clients.[17]