Demand Media (behind sites like eHow.com) has a special algorithm which finds hot and profitable keywords, converts them into article titles, and has writers post articles and video producers make short videos on those subjects. The site is very focused on finding hot words people are typing into Google (probably with a longtail and low competition focus), and those words which pay highly on Adsense. They put out something crazy like 4000 videos and articles everyday and have revenues of $73 million from this content farm. eHow.com is heavily monetized by Adsense so a large proportion of that $73 million will come from Adsense. Anyway, you can apply what they do in your own business. Here is one way to do it... http://www.searchenginejournal.com/demand-media-case-study/24431/ I prefer more of a human touch in producing content and deciding topics, but the principle of focusing hugely on the longtail and creating lots of content to attract Google traffic is the same. Study what Demand Media does and you'll learn what pro Adsense/Google marketers do on a massive scale.
Because Demand's Media content farm business is based heavily on Google. They look for the higher traffic keywords people are typing into Google, and also the ones which have a high Adsence CPC. They are heavily monetized by Adsense. They also are pretty smart when it comes to ranking well in Google and have been caught out doing some greyhat SEO. If you want to look to a company that understands Google and generates millions in revenue from it then look to Demand Media.