You can find discussion on the web where people think that removing Adsense from one of their account's websites where the ads perform poorly results in less Smart Pricing effect and thus higher earnings for their account as a whole. I have no first hand experience with this.
Just within the last 3 weeks or so I have had this experience.
My pages utilize 3 AdLink units. Historically, one has been buried down in the footer. Admittedly, that unit was positioned at the tail end of a menu. The appearance/format of the menu vs. AdLink links was different ("unordered list" of text links vs. oval buttons), so I doubt it was really accounting for many accidental clicks. I think that unit's main crime was simply that no one really ever saw it.
Recently I have brought that unit up into the text portion of my page. Concurrently, my RPM has risen on the order of 25 to 30%. It's my impression that the added income from this unit being seen and clicked on doesn't explain that increase by itself. I really think that the SmartPricing algo likes that positioning better and I am being rewarded for it.
Possibly this last week or so the increase in RPM is more solidly in the 25% range rather than the 30% one, so possibly Smart Pricing is learning and kicking back in. I don't know.
I assume that I am being rewarded for increasing the visibility of the unit and putting it "in text". (I'm assuming that somehow this brings higher quality clicks.)
Or possibly the income increase I have experienced is totally coincidental, who knows.
I googled around some to learn about examples of when SmartPricing kicks in vs. doesn't (like ad placements and such). I found essentially no information.