Relationship between SEO and the search engines
Due to the high value and targeting of search results, there is potential for an adversarial relationship between search engines and SEOs. 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. All of the main search engines like Google's, Yahoo!'s, MSN's and Ask.com's provide information/guidelines to help with site optimization.
Google has a Sitemaps program to help webmasters learn if Google is having any problems indexing their website and also provides data on Google traffic to the website.
Yahoo! has Site Explorer that provides a way to submit your URLs for free (like MSN/Google), determine how many pages are in the Yahoo! index and drill down on inlinks to deep pages. Yahoo! has an Ambassador Program and Google has a program for qualifying Google Advertising Professionals.
Those who operate search engines recognize quickly that some web masters (specifically search engine optimizers) are making bold efforts to rank well in their search engines, even by manipulating the page rankings in search results. For Infoseek and some other search engines, optimizers were grabbing the source code of the top-ranking pages and placing it in their pages.
Search engines have always frowned upon those aggressive SEO practices; going to the extent of banning the pages in the search listings. The more aggressive site owners' generating automated sites for better ranking, suffered much search engine wrath; their domains were banned from the search engines.
Today, many search engine optimization companies employ long-term, low-risk strategies. Some SEO firms that do employ high-risk strategies for their own affiliate, lead-generation, or content sites, instead of taking the risk on client's web sites.