While the launch of AdSense has been providing a new source of revenues for websites, Google ads and affiliate programs shouldn’t be seen as competitors but rather as complementary advertising models.
Online revenues can be maximized through a strategic placement of creatives on a site.
With their customized look and feel, AdSense ads work best when blending in your content, because they are relevant and not too intrusive. The best way to get the most out of AdSense is to use AdWords’ Keyword tool to find out which pages are the most appropriate for AdSense, in terms of cost per click.
Affiliate links work best when included in the navigation—especially when they match the content of your site—while banners are best suited for typical ad-emplacements such as headers as well as right and left hand side columns.