See also: search engine optimization
Search engine optimization methods are techniques used by webmasters to get more visibility for their sites in search engine results pages.
The leading search engines, such as Google 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. Some search engines, notably Yahoo!, operate a paid submission service that guarantee crawling for either a set fee or cost per click. Such programs usually guarantee inclusion in the database, but do not guarantee specific ranking within the search results. Two major directories, the Yahoo Directory and the Open Directory Project both require manual submission and human editorial review. Google offers Google Webmaster Tools, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that aren't discoverable by automatically following links.
Search engine crawlers may look at a number of different factors when crawling a site. Not every page is indexed by the search engines. Distance of pages from the root directory of a site may also be a factor in whether or not pages get crawled.
A variety of other methods are employed to get a webpage indexed and shown higher in the results and often a combination of these methods are used as part of a search engine optimization campaign.
Cross linking between pages of the same website. Giving more links to main pages of the website, to increase PageRank used by search engines. Linking from other websites, including link farming and comment spam.
Keyword rich text in the webpage and key phrases, so as to match all search queries. Adding relevant keywords to a web page meta tags, including keyword stuffing.
URL normalization for webpages with multiple urls, using "canonical" meta tag.
A backlink from a Web directory.
SEO Trending based on recent search behaviour using tools like Google Insights for Search.
Media Content creation like press releases and online news letters to generate an amount of incoming links
Gray hat techniques
Gray hat techniques are those that are neither really white nor black hat. Some of these gray hat techniques may be argued either way. These techniques might have some risk associated with them. A very good example of such a technique is purchasing links. The average price for a text link depends on the perceived authority of the linking page.. The authority is sometimes measured by Google's PageRank, although this is not necessarily an accurate way of determining the importance of a page.
While Google is against sale and purchase of links there are people who subscribe to online magazines, memberships and other resources for the purpose of getting a link back to their website.
Another widely used gray hat technique is a webmaster creating multiple 'micro-sites' which he or she controls for the sole purpose of cross linking to the target site. Since it is the same owner of all the micro-sites, this is a violation of the principles of the search engine's algorithms (by self-linking) but since ownership of sites is not traceable by search engines it is impossible to detect and therefore they can appear as different sites, especially when using separate Class-C IPs.