You can confer some of your site's reputation to another site when your site links to it. Sometimes users can take advantage of this by adding links to their own site in your comment sections or message boards. Or sometimes you might mention a site in a negative way and don't want to confer any of your reputation upon it. For example, imagine that you're writing a blog post on the topic of comment spamming and you want to call out a site that recently comment spammed your blog. You want to warn others of the site, so you include the link to it in your content; however, you certainly don't want to give the site some of your reputation from your link. This would be a good time to use nofollow.
In 2013, the Tenth Circuit Court of Appeals held in Lens.com, Inc. v. 1-800 Contacts, Inc. that online contact lens seller Lens.com did not commit trademark infringement when it purchased search advertisements using competitor 1-800 Contacts' federally registered 1800 CONTACTS trademark as a keyword. In August 2016, the Federal Trade Commission filed an administrative complaint against 1-800 Contacts alleging, among other things, that its trademark enforcement practices in the search engine marketing space have unreasonably restrained competition in violation of the FTC Act. 1-800 Contacts has denied all wrongdoing and is scheduled to appear before an FTC administrative law judge in April 2017.
However, while bidding $1,000 on every keyword and ranking #1 for every relevant search sounds nice in theory, most businesses have to play a balancing game between ranking higher and paying too much for clicks. After all, if it costs $17.56 to rank in position #1, but you can only afford to pay $5.00 per click, bidding $1,000 on a keyword to guarantee yourself the #1 position would be a great way to bid yourself out of business.
You should build a website to benefit your users, and any optimization should be geared toward making the user experience better. One of those users is a search engine, which helps other users discover your content. Search Engine Optimization is about helping search engines understand and present content. Your site may be smaller or larger than our example site and offer vastly different content, but the optimization topics we discuss below should apply to sites of all sizes and types. We hope our guide gives you some fresh ideas on how to improve your website, and we'd love to hear your questions, feedback, and success stories in the Google Webmaster Help Forum1.
Search engines reward you when sites link to yours – they assume that your site must be valuable and you’ll rank higher in search results. And the higher the “rank” of the sites that link to you, the more they count in your own ranking. You want links from popular industry authorities, recognized directories, and reputable companies and organizations.
Optimizing a website may involve editing its content, adding content, modifying HTML, and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.