Why Are AdSense Clicks are invalid?

Many times you might have seen that although you got some clicks on your ads but there are no changes in your earnings as seen on your Google Adsense Earnings Reports.

This is quite a commonly occurring and you should not get agitated because of this. There are three most common reasons for this happening:

1. Clicks are invalid Clicks on your ad units can be deemed invalid if they are contrary to the Adsense TOS. The clicks are deemed invalid if the Google is suspicious of the clicking activity. This may be due to multiple clicks happening from a single IP or very quick clicks (suspicious Click Robot activity) in a short period of time.
2. PSA being displayed on your site Sometimes when the Adsense has not yet crawled your site to get to know about the site keywords, the program displays Public Service Adverts. These are unpaid adverts dealing with public welfare activities like the call for donations of accident victims etc. If there are any clicks on such sites, then although the clicks are registered, but there is no earning.
3. CPM ads Some ads are configured to generate revenue not for clicks but for no of impressions eg. If the ad is configured to pay you $0.05 for 10 impressions, then for a first few impressions the value generated is less that $0.01, so the earning generated would only be shown till you reach a value more than $0.01.

I hope the above clears the doubts some of you might have in this regard.