I don't like depending solely on Webmaster Welfare (Adsense). I prefer to get my website income from multiple streams, placing the heaviest emphasis on affiliate marketing. However, we create our websites for users. That means that we focus on informing the visitor and not simply writing posts with the sole goal being to make money with affiliate marketing.
You can use Adsense targeted channels to track the performance of specific groups of ads unit. As you can define the ads placement using your custom channel.