Discrepancies and Sources
Discrepancies often exist in mobile advertising when two or more systems are used to count the same event. Most commonly this is the difference between the first and third-party ad servers, but often can be exacerbated by analytics counts of page views or fourth-party data or rich media vendors. This discussion pertains to first and third-party discrepancies.
Some amount of discrepancy is completely inevitable when two different ad servers are used in delivery of any digital campaign. This is because the process of handing off delivery from the first to the second involves an exchange between the client’s device and each ad server over the open internet. The process can be interrupted in a number of ways: users clicking the back button, devices losing connection, or a failure on any server between the device and either ad server.
The second source is a difference in methodology. As illustrated, most of today’s ad servers were originally architected for desktop environments, recording an impression on ad request. An ad server like Medialets doesn’t count the impression until it has successfully delivered and the creative has rendered on a user's device. This methodology adheres to the latest MRC/MMA/IAB Mobile Served Ad Impression Measurement Guidelines.
The third source, and the most common source of non-inherent discrepancies, is user error. The mobile world has fewer standard processes for trafficking, and the old desktop rules don’t always apply. This leads to frequent trafficking error. If you have any questions on tag implementation, please reference Servo Tag Implementation Guides.