Webmasters and search engines ?

By 1997 search engines recognized that some webmasters were making efforts to rank well in their search engines, and even manipulating the page rankings in search results. Early search engines, such as Infoseek, adjusted their algorithms to prevent webmasters from manipulating rankings by stuffing pages with excessive or irrelevant keywords.[12]

Due to the high marketing value of targeted search results, there is potential for an adversarial relationship between search engines and SEOs. In 2005, an annual conference, AIRWeb, Adversarial Information Retrieval on the Web,[13] was created to discuss and minimize the damaging effects of aggressive web content providers.

SEO companies that employ overly aggressive techniques can get their client websites banned from the search results. In 2005, the Wall Street Journal profiled a company, Traffic Power, that allegedly used high-risk techniques and failed to disclose those risks to its clients.[14] Wired reported the same company sued a blogger for mentioning that they were banned.[15] Google's Matt Cutts later confirmed that Google did in fact ban Traffic Power and some of its clients.[16]

Some search engines have also reached out to the SEO industry, and are frequent sponsors and guests at SEO conferences and seminars. In fact, with the advent of paid inclusion, some search engines now have a vested interest in the health of the optimization community. Major search engines provide information and guidelines to help with site optimization.[17][18][19] Google has a Sitemaps program[20] to help webmasters learn if Google is having any problems indexing their website and also provides data on Google traffic to the website. Yahoo! Site Explorer provides a way for webmasters to submit URLs, determine how many pages are in the Yahoo! index and view link information.[21]

Getting listings

The leading search engines, Google, Yahoo! and Microsoft, 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.[22] Such programs usually guarantee inclusion in the database, but do not guarantee specific ranking within the search results.[23] Yahoo's paid inclusion program has drawn criticism from advertisers and competitors.[24] Two major directories, the Yahoo Directory and the Open Directory Project both require manual submission and human editorial review.[25] Google offers Google Sitemaps, for which an XML type 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.[26]

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.[27]

Preventing listings
Main article: robots.txt

To avoid undesirable search listings, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots. When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed, and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.