Optimization techniques are highly tuned to the dominant search engines in the target market. The search engines' market shares vary from market to market, as does competition. In 2003, Danny Sullivan stated that Google represented about 75% of all searches. In markets outside the United States, Google's share is often larger, and Google remains the dominant search engine worldwide as of 2007. As of 2006, Google had an 85–90% market share in Germany. While there were hundreds of SEO firms in the US at that time, there were only about five in Germany. As of June 2008, the market share of Google in the UK was close to 90% according to Hitwise. That market share is achieved in a number of countries.
QUOTE: “Tell visitors clearly that the page they’re looking for can’t be found. Use language that is friendly and inviting. Make sure your 404 page uses the same look and feel (including navigation) as the rest of your site. Consider adding links to your most popular articles or posts, as well as a link to your site’s home page. Think about providing a way for users to report a broken link. No matter how beautiful and useful your custom 404 page, you probably don’t want it to appear in Google search results. In order to prevent 404 pages from being indexed by Google and other search engines, make sure that your webserver returns an actual 404 HTTP status code when a missing page is requested.” Google, 2018
OBSERVATION – You can have the content and the links – but if your site falls short on even a single user satisfaction signal (even if it is picked up by the algorithm, and not a human reviewer) then your rankings for particular terms could collapse – OR – rankings can be held back – IF Google thinks your organisation, with its resources, or ‘reputation, should be delivering a better user experience to users.
The leading search engines, such as Google, Bing and Yahoo!, use crawlers to find pages for their algorithmic search results. Pages that are linked from other search engine indexed pages do not need to be submitted because they are found automatically. The Yahoo! Directory and DMOZ, two major directories which closed in 2014 and 2017 respectively, both required manual submission and human editorial review. Google offers Google Search Console, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that are not discoverable by automatically following links in addition to their URL submission console. Yahoo! formerly operated a paid submission service that guaranteed crawling for a cost per click; however, this practice was discontinued in 2009.
The SEO starter guide describes much of what your SEO will do for you. Although you don't need to know this guide well yourself if you're hiring a professional to do the work for you, it is useful to be familiar with these techniques, so that you can be aware if an SEO wants to use a technique that is not recommended or, worse, strongly discouraged.
Critics will point out the higher the cost of expert SEO, the more cost-effective Adwords becomes, but Adwords will only get more expensive, too. At some point, if you want to compete online, your going to HAVE to build a quality website, with a unique offering to satisfy returning visitors – the sooner you start, the sooner you’ll start to see results.
Another excellent guide is Google’s “Search Engine Optimization Starter Guide.” This is a free PDF download that covers basic tips that Google provides to its own employees on how to get listed. You’ll find it here. Also well worth checking out is Moz’s “Beginner’s Guide To SEO,” which you’ll find here, and the SEO Success Pyramid from Small Business Search Marketing.