Why do my reports show clicks with no associated earnings?
If you see clicks with no associated earnings in your AdSense for content reports, it may be that you received some invalid clicks during this date range.
In order to protect the interests of our publishers as well as those of our advertisers, Google monitors clicks on Google CPC ads to prevent any abuse of the AdSense program. Google's proprietary technology analyzes all ad clicks for any invalid click activity that is intended to artificially drive up an advertiser's clicks or a publisher's earnings.
Clicks deemed by our monitoring system to be invalid will appear in your reports. However, since advertisers are not charged for clicks deemed to be invalid, publishers do not receive any revenue for these clicks. Consequently, you may on occasion notice clicks with no associated revenue. Please rest assured that your account is being properly credited for all valid clicks.