Click fraud is a very real concern for anybody who is doing CPC marketing. Click fraud involves any artificially created click on your ad. A human being can create these clicks, or a software program called a clickbot can create them.
These clicks unfortunately cost you money.
The hard part is identifying click fraud. In order to do this you need to constantly monitor your campaigns, keeping a watchful eye out for any abnormalities. You need to pay attention to your campaigns established trends and watch for any divergence in those trends. For example, suppose you have an Adgroup that averages an 8% CTR. Minor variations to this CTR are normal and expected. What happens, however, if this Adgroup spikes to a 15% CTR without warning? What do you do?
The first thing you need to do in such a case is check to see if there are any logical reasons for this spike. For example, was there some media coverage on your industry that would cause an increase in searches for your keywords? There can be perfectly reasonable explanations for unexpected traffic spikes. Did you experience an increase in sales? This is another good indicator of real traffic. If your sales...