These guidelines are in place because of the ethical outlook of search engines: the organic web should be a place of open opportunity, without any monetized value influencing organic listings.
Many webmasters and SEOs choose to ignore these guidelines and take the risk of artificially influencing their website's PageRank. This can be a hazardous choice and is not endorsed by ethical digital marketing companies.
Some webmasters and SEOs may choose to take the risk because they assume that search engines are not capable of deciphering whether a link is of editorial choice or paid value. This is certainly not the case; search engines employ a number of cunning tactics to decipher whether a link is placed on a website via editorial merit or as a result of a monetary transaction.
Visualisation
The common layout of a website holds many clues when it comes to identifying paid links. Webmasters typically buy links on the main navigation or footer areas of a webpage and these links are often purchased site-wide e.g. they appear on every page. Search engines are very intelligent machines; they make heavy use of mass data-mining skills and data-mining can also be used in visualisation.
When looking at a captured page screenshot, a human could easily decide which elements of the page are which - and so can search engines.
If you take a screenshot of every page on a site and compare them all, you can easily identify that the main body section is frequently the only section that regularly changes from page to page - thus rendering the rest of the page's contents as navigational elements. Therefore, the positioning of a link is a way that search engines can de-value the page. It's also worth noting that not every link on a page is treated the same when it comes to passing PageRank.
Recently, Matt Cutts, head of Google's webspam team, announced that new PageRank values would be visible within the Google Toolbar. There has been much debate about how emerging techniques applied by Google to improve the quality of the web - such as the potential use of visualisation - have influenced this toolbar export.
This is only one way search engines like Google could potentially highlight and de-value a paid link. Other methods include charting link growth trends, reviewing trends in anchor text or even using a human engineer to manually review websites. By logging into forums that openly display webmasters selling links and acting as a buyer, search engines can gather data on who is buying and selling links.
Bigmouthmedia would like to think that whenever unethical webmasters think up new ways to try gaming search engine rankings, search engines will be a step ahead and ready to combat these underhand actions.
