The greatest strength of AdWords has always been the fantastic metrics. As a PPC manager for an internet marketing agency I can attest to the fact that clients love knowing exactly how much they’re spending, how many visitors they get for that money and how many conversions it produces. However, Google isn’t resting on its laurels.
Google Campaign Insights
In short, Campaign Insights is an attempt to attach metrics to impressions in the content network (currently a money black hole for many advertisers) by utilizing the massive amount of search data that Google possesses. These metrics are generated by comparing two groups: one large group who saw your ads and one large group that didn’t. Campaign Insights then compares search behavior and visits to your site to determine if the impressions had any effect on their behavior. That is pretty dang cool.
For those people who worry about privacy concerns, Google only uses data from Google Toolbar users who have opted in to enhanced features. Also, the data is anonymized as well as obfuscated by the size of the groups being analyzed. Translation to all that jargon: nobody knows your search history.