Checked my stats today, couldn't believe it. I calculate about 9% CTR from exit link tracker on statscounter. None of the clicks registered in adsense! I notice a pattern in the stats. I kind of have a theory on why they're not counted. But anybody here might have anything in mind?
Don't dwell on the small things, man. I talked about this a long time ago. It could be that the clicks are invalid. It could also be a number of other things that we're just not aware of. Maybe the ad clicker isn't converting well enough or staying on the advertisers' site long enough for the click to count? Who knows, really? But there's no point in dwelling on something you cannot change. When in doubt, you can always shoot an email to AdSense support. They will respond if they think your email is important.
ttomp is right. They could be invalid clicks, or simply that the click counter you are using is counting clicks to areas other than the ads themselve. Either way I wouldn't worry about it. Google is a billion dollar corporation and it didn't get their scamming people.
I am quite surprised by this actually. I have personally had situations where I get plenty of clicks just suddenly on one ad (which I assume was my competitors or a bot), they get REGISTERED in adsense, but they don't count as income. Obviously google picked up that it was very dodgy traffic and didn't pay out for them. But what surprises me is that your didn't even register in adsense itself. My guess is that they've either totally changed the way they deal with invalid clicks by not even counting them, or your script could be reading the wrong position, but from what it seems like, they were probably fishy clicks, whats your average day clicks on this certain ad?
I don't know how accurate the tracker is but upon closer look, about half the clicks are h=15 so they're on ad units. But that still means 40 clicks didn't register.