Tracking your ads' clicks gives you reliable information about how well your campaign is performing. PPC engines include some detailed tracking information in your advertiser's control panel. To capture a maximum amount of data, it is advisable to also install statistical tracking on your website and record your referring URLs.

Most of the time, you'll notice that the number of clicks tracked by yourself is 15% to 30% more than the clicks the PPC engine reports. This is because reputable PPC engines have installed anti-fraud mechanisms that can catch competitors who are repeatedly clicking on your listings and wasting your bid budget. They will count multiple clicks within a timeframe originating from the same computer as only one click through, while your own log will usually register the multiple clicks.

In addition to competitors who will click away your budget, there are actually businesses set up where workers do nothing all day but click on pay-per-click ads placed by their clients' competitors in order to run out an account's budget as quickly as possible. Unfortunately, click fraud is a reality with current PPC technology, and even though the PPC engines attempt to squash it, advertisers must be vigilant in monitoring their campaigns and reporting suspected fraudulent activity.

Related to ad click tracking, AdWords recently unveiled a ROI tracking mechanism that places a small amount of JavaScript code on your lead completion pages (for example, a "success" page that a user arrives at after completing a request form on your site). When a visitor who clicked one of your ads arrives on your completion page, a notification is sent back to your AdWords control panel allowing you to see which clicks were converted into leads.