Google specialists carefully monitor clicks and impressions on Google ads in order to protect your interests as well as those of Google advertisers. To do this, Google use both automated systems and human reviews, analyzing all ad clicks and impressions for any invalid traffic that may artificially drive up an advertiser’s costs or a publisher’s earnings.
Google’s proprietary technology analyzes clicks and impressions to determine whether they fit a pattern of use that may artificially drive up an advertiser’s costs or a publisher’s earnings. Google system uses sophisticated filters to distinguish between traffic generated through normal use by users and traffic that may pose a risk to Google advertisers.
Some examples of this include clicks or impressions generated by unethical users, automated robots and traffic sources, and publishers encouraging clicks on their ads. Google system enables us to filter out most invalid traffic, and Google advertisers are not charged for this traffic.
Learn more at Google Ad Traffic Quality Resource Center.
In addition to Google automated system, Google have a team dedicated to detecting invalid traffic using several specialized tools and a wide variety of techniques based on extensive experience tracking and monitoring user behavior and analyzing scenarios. Google continually upgrade Google detection mechanisms to proactively combat invalid traffic.
To prevent invalid traffic in your account, ensure that your ad implementation complies with Google Program policies, and that you haven’t paid for traffic from an unreliable source.
Learn more in AdSense policies: a beginner’s guide.
If you’re concerned that a third party may be generating invalid traffic on your ads, see Google tips for preventing invalid traffic.