Adsense or Affiliate Programs?

As my sites get more and more search engine traffic, I am faced with trying to figure out how to best monetize my traffic. I am currently using mainly Google Adsense ads, but since I have added more affiliate programs to pages that are getting traffic I am noticing a very nice increase in my monthly income.

I have read in many places that affiliate ads that are prominently displayed will take away from your adsense income. I must agree that on sites where my affiliate programs are simply generally related to my site as a whole, my affiliate income is almost non-existent. However lately I have been studying my traffic logs closely and looking at the search phrases people have been using to find my pages.

Once I have determined the key phrase, I then narrow it down to the page they found when they typed in that phrase. Once this is established I search high and low for an affiliate product that matches