google anti spam

Google Anti Spam

Google states "a typical 'legitimate' document attracts back links slowly.
For instance, someone using Google's AdSense program would use a program or hire cheap labor to continuously click on the ads on their own web page, thus generating unearned revenue at the cost of the advertiser.
Alternatively, someone using something like Yahoo or Google's AdWords program would generate clicks on a Competitors ads at Google, costing the competitor money.
Spambots, and even Google, do not always obey the robots.
This is how google defines search engine spam (taken from a google patent): An attempt to "obtain higher ranking, and thus better placement in search results by exchanging links, purchasing links, or gaining links from documents without editorial discretion on making links.
"An e-mail address obtained from a free e-mail provider (such as Hotmail, Google, Yahoo, etc.

Google Anti Spam