The accuracy of reports are affected by ad blockers, different definition of unique visitors and our statistical method in collecting and presenting data.
Ad Blockers
When your visitors use an ad blocking software on their computers, they see the web pages but no
ad. Since they do not see ads, no
impression is recorded in our system. An impression is recorded when a
beacon, a tracking image, is successfully loaded into the browser. An impression is not yet recorded when the
serving code is delivered. Ad blockers are designed to prevent images from loading and therefore the tracking image would not be requested from the visitor computer.
Definition of Unique
There might be discrepancies between the numbers reported by our system and other systems. Our
unique impression number is defined as per visitor (IP address) per ad within 24 hours. For other system, it might be per visitor within another time interval other than a 24-hour period.
Collecting and Presenting Data
Numeric counters are recorded for every single impressions, clicks and conversions. On the other hand,
detailed information about your visitors are collected on a representative sampling basis.
Reporting 
