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.
Search engine optimization (SEO) is often about making small modifications to parts of your website. When viewed individually, these changes might seem like incremental improvements, but when combined with other optimizations, they could have a noticeable impact on your site's user experience and performance in organic search results. You're likely already familiar with many of the topics in this guide, because they're essential ingredients for any web page, but you may not be making the most out of them.
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.

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.[10][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.[11] 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.[12]