Quick Adsense Question, Someone has to know the Answer..

The issue here, Paul, as I've understood it, is that Google a special kind of "auction" inside its algo that determines WHICH ads show in WHICH ad block. Typically, they reserve the first displaying ad box for the highest CPC advertiser(s). So the first unit, no matter how many are displayed, will have the highest CPC and potential EPC in general.

If you display your full allocation of units all over, you have a bunch of additional "eyeball attractors" on your site that - if they distract the user into clicking there - earn you less money. Google allows this on your page because ultimately, if the first unit doesn't get the click, they're hedging their bets on the others as a last ditch. But that doesn't help you earn more money because you've got a lot of ads which distract the user and then they might not even click through.

If you're having trouble with getting high quality ads and thus needing to toss in lots of units to make up for it, consider using Google's ad-section-targeting markup in your HTML content to help Google better understand exactly what your page is about.

Remember, Google's goal is to make money. The reason they show the best ad first is because they want that one clicked so they earn more (and you, by extension, earn more too). Google has a vested interest in showing the highest-paying ad and so do you. So if you help Google to better know which ads to display with targeted markup, you'll get more relevant ads.

There is quite a lot on the forum about AdSense placement methodologies. I've found XFactor's stuff to be great and I use it myself.

If you want more units, just be sure that in your HTML layout and markup that you have the best performing ad unit placement first in your code, so it will attract the high EPC ads.

Hope that's useful. It's a little beyond the original question, but I think relevant to how this thread evolved.