I cited a day when My Blog Log reported 10 AdSense outgoing clicks while Google said that only one click was made on the site.
It’s true that AdSense Publishers have no concrete way to calculate the exact number of Adsense clicks made on their sites (but they can approximate with Google Analytics).
Coming to the difference between Google Reports and MyBlogLog stats, I can think of two reasons
1. Google does discount some clicks on AdSense ads as invalid though that number is less than 10% according to Shuman Ghosemajumder of the click-fraud team at Google.
2. Google displays a mix of CPC and CPM ads – For MyBlogLog, a click on a CPM ad is no different from a click on a CPC ad but from Google’s perspective, clicks on CPM ads do not matter because the publishers get paid even without clicks.
Am not sure but looks like Google is not display the click data for CPM ads in Adsense Reports – hence the difference between My Blog Log and Adsense numbers.