Well, I don't know about "ironic", but it's quite a revelation. While wondering if my Adsense ads were undercutting my affiliate sales (since the Adsense ads tend to display merchants selling the product I'm also selling on a particular page) I decided to remove the Adsense code from almost half of my pages. That was yesterday. Today, my Adsense earnings are -- ready? -- at about the same level as every other day! So that means the ads that I took out didn't effect my earnings at all! I have no idea what this means, except maybe this (and I stress the maybe part): I get the feeling only half of my site is converting! And I just figured out which half it is! Then again, it's just a wild guess, and it's only been one day. We'll see in a week...
Google reports are often a couple of days behind what you see. I had a similar question and I asked google why were the reports inaccurate, they told me that the reports were often 1, 2, 3 days behind. AdSense has the ability to block up to 200 urls from the adsense ads on your site, you could go in and enter all the urls of your competitors. HTH
Your competitors with Adwords are conveniently listed to the right side of a Google search page. I set results shown to 100, and start my list. Be careful, depending on your content you can eliminate all ads too by banning everybody.
Buy an advanced adsense tracker, once I relized 10% of my ads were making 70% of my adsense income, I removed the ads from the non-performing pages, put up affiliate links, and doubled my income. My adsense checks are no longer sent via UPS, but I'm not complaining.
are you using adsense channels to see which parts of your site do well and which don't? if not, i'd highly recommend it. this will help you decide where adsense can be dropped in favor of other programs (on certain pages that is)
I use: http://www.related-pages.com/astracker.aspx. (not assosicated with the site at all, not an affiliate link etc...). It costs $99.00, and once you figure out what you can do with the information, the payback will come quickly. IMHO, one of the better purchases I have made in the last few months.