Discrepancy occurs whenever we compare the performance data between two sources. Ad discrepancy in digital advertising is very common when we compare the ad campaign performance with other sources. We should investigate the discrepancy issue whenever it is beyond the accepted level.
Here we are going to discuss the below topics,
What Is Discrepancy In Digital Advertising?
How To Investigate Ad Discrepancy?
What Are The Reasons For Ad Discrepancy?
What Is Ad Discrepancy?
Ad Discrepancy is a difference between the performance data from two sources. Two parties following different methodologies to count the performance cause discrepancy. Actually, it’s normal in digital advertising. But, if the discrepancy percentage exceeds the accepted level then we should investigate and find the reason that causes the discrepancy.
Let’s consider, you are generating the ad tag from third party ad servers like DCM, Sizmek, Nexd, etc and upload the generated third party ad tag on demand side platforms like DV360, Amobee,etc. Once campaigns live, the performance data like impressions, clicks,etc will be recorded on the demand side platform as well as on the third party platform. Some clients are okay with either demand side platform numbers or third party platform numbers. But some clients match both performance reports and check for discrepancies.
Normally, both reports should not match exactly. Because, 3rd party ad server and demand side platforms follow different methodologies to count the performance, impression, click, actions etc. So, it won’t match exactly.
But, both sources know each other’s technologies and set maximum acceptable discrepancy range. As per market standards, 10% impression discrepancy is acceptable. In this situation, if our campaign’s discrepancy exceeds 10% then we should investigate and find the reason for the discrepancy.
How To Calculate Discrepancy?
Normally, the discrepancy is calculated in percentage. Below is the simple formula used to calculate the ad discrepancy,
(Your Number – Their Number)/Their Number = % Discrepancy
For example, You are working in the demand side platform side and you are using 3rd party ad tags for your campaign. Your account manager provided the 3rd party ad server performance report and asked you to investigate the high discrepancy issue.
Now, you need to compare the 3rd party ad tag performance numbers with the demand side platforms performance number. If you are running three ad tags then you have to create the discrepancy report as below,
| Creative Name | DSP Impressions | 3rd Party Impressions | Discrepancy (%) |
| Creative A | 5000 | 4000 | 25% |
| Creative B | 4000 | 3800 | 5% |
| Creative C | 5000 | 4600 | 9% |
You need to prepare the discrepancy report like this. If all the creative’s discrepancy percentages are within the acceptable range then you can inform your account manager and there is no need to investigate further. If it is not within the acceptable range then you should investigate to find the reason.
How To Investigate Ad Discrepancy?
1. Check Your Report
Sometimes, we may incorrectly prepare the discrepancy report. So, please validate your raw data and discrepancy report once again. Please confirm the below,
- You are exporting raw data for same date range
- You are exporting raw data for same campaign
- You are following same breakdown
2. Blocking Tags
Many advertisers are using Integral Ad Science, Double Verify & additional vendors blocking tags to make sure their advertisement only shows on quality web pages. The third party ad tags wrapped with these blocking tags and uploaded in the demand side platforms.
When an advertiser wins the bid request, the demand side platform counts the impression. Meanwhile, the browser first contacts the IAS or Doubleverify blocking vendors to fetch the ad preview because the ad tag is wrapped with IAS or Doubleverify blocking vendor tags. These vendors check the page quality. If the page quality meets the standards, they allow the third party ad tag to send the ad preview to the browser. Once an ad is loaded, the third party ad server counts the impressions. If the page quality does not meet the standards, then the ad is blocked and stopped showing on the web page. In this situation, IAS or Doubleverify vendors count the blocked impression and the third party won’t count the impression because it wasn’t loaded on the web page.
So, we should sum the blocked impression count with a third party ad server impression count and then match it with the demand side platform’s impression count to prepare the discrepancy report.
3. Validate The Ad Setup
Next, please check the ad setup in the demand side platform and confirm whether you have inserted cachebuster macro and click macro properly. If you haven’t inserted the cachebuster and click macros properly then it should lead to discrepancy. [Please read this post to understand more about Macro : What is Macro? Why Is Macro Required? What Will Happen If Macro Isn’t Implemented?]
4. Run Deep Level Report
Other than demand side platform & third party ad server, the discrepancy may happen due to publisher side issues like page load issue, connection interruption, etc. To investigate the discrepancy issue further, we need to run or get a more deep level report from both sources.
What Are The Reasons For Ad Discrepancy?
1. Different Measurement Algorithms
Every platform has its own measurement algorithms to track the performance. For example, demand side platforms (like dv360/amobee etc) follow different algorithms to record impressions, clicks etc. Likely, third party ad servers follow different algorithms to record impressions, clicks etc. This measurement algorithm differs between each dsp and each 3rd party ad server.
For instance, the demand side platform counts the impression once it wins the bid and the third party ad server counts the impression once the ad is fully loaded on the web page. Here, two parties are following different rules to record impressions. So, there should be a difference in the counting. If it is at the acceptable range then we can ignore this issue. Otherwise, we need to investigate this issue further.
2. Ad Blocker Addons
Nowadays, most of the users are using Ad Block addons on their browsers. Ad blockers are developed to stop showing advertisements on website pages. Ad blockers block the scripts or ad tags. Ad blockers are also developed with various methods. So, it can also create discrepancy problems.
3. Missed To Insert Macro
We should insert appropriate macros on the third party ad tag. If you haven’t inserted the macros properly then it should lead to discrepancy. [Please read this post to understand more about Macro : What is Macro? Why Is Macro Required? What Will Happen If Macro Isn’t Implemented?]
4. Platform wide issue
Sometimes, entire platform face an issue to track the performances on certain dates or data latency also causes higher discrepancy. So, we should make sure whether both platforms work well on those days.
Conclusion : Discrepancy
Discrepancy is a common problem when we compare the performance data from two different platforms. We measure the discrepancy in percentage. If the discrepancy percentage does not exceed the acceptable range then we can ignore the discrepancy issue. Otherwise, we should investigate and find the reason that causes the discrepancy. So that we can avoid the discrepancy problem for the next ad campaign.
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