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.
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. 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. 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. This is an ethical way for managers to send messages about their advertisements and products to their consumers.
Many blogging software packages automatically nofollow user comments, but those that don't can most likely be manually edited to do this. This advice also goes for other areas of your site that may involve user-generated content, such as guest books, forums, shout-boards, referrer listings, etc. If you're willing to vouch for links added by third parties (for example, if a commenter is trusted on your site), then there's no need to use nofollow on links; however, linking to sites that Google considers spammy can affect the reputation of your own site. The Webmaster Help Center has more tips on avoiding comment spam40, for example by using CAPTCHAs and turning on comment moderation.
Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag or index files in engines like ALIWEB. Meta tags provide a guide to each page's content. Using metadata to index pages was found to be less than reliable, however, because the webmaster's choice of keywords in the meta tag could potentially be an inaccurate representation of the site's actual content. Inaccurate, incomplete, and inconsistent data in meta tags could and did cause pages to rank for irrelevant searches.[dubious – discuss] Web content providers also manipulated some attributes within the HTML source of a page in an attempt to rank well in search engines. By 1997, search engine designers recognized that webmasters were making efforts to rank well in their search engine, and that some webmasters were even manipulating their rankings in search results by stuffing pages with excessive or irrelevant keywords. Early search engines, such as Altavista and Infoseek, adjusted their algorithms to prevent webmasters from manipulating rankings.