Hi- How would google determine the sites are of related category ? Does anyone have any theories on it ? How "g" penalizes for linking from unrelated contents ? Thanks in advance.
Basically, they simply look for repeat keywords at your site and display ads that target these keywords. Thus, when you enroll in the AdSence program you should expect that a considerable part of ads displayed at your site will be those from your direct competitors.
The spiders are programmed to look for common denominators such as San Diego Surfing, San Diego Real Estate etc. Is a lot more complicated and complex of course. Was that the question?