Reporting discrepancies
When viewing ESP data versus GAM or our reporting data, you will see discrepancies for a variety of reasons.
Different providers may count metrics differently. Some of the factors that can contribute to click and impression discrepancies when comparing our numbers to another provider are:
Time Zone Differences
All times at OpenWeb are always presented in UTC. Please check the time zones of your ESP and Google Ad Manager account if you are using an ad server to ensure that you are basing the comparison from your previous provider on the same time zone.
Difference Between Gross and Net Unique Impressions and Clicks
Some providers will present the gross number of impressions and clicks, that is the number of impressions without any filtering taking place. Our network shows the net unique numbers of impressions. This means that we will show impressions that are valid and will only show how many distinct user impressions were served per day. It is likely that other providers would show a higher number in this instance. If you require gross numbers, please reach out to your Account Manager who will be able to assist you with this.
Filtering
In some instances, even though the other provider reports net numbers, there can still be a discrepancy. This is in fact a very common occurrence due to differences in methodologies amongst providers. Below are a few ways we filters out impressions.
Invalid Traffic
We remove what we consider to be invalid traffic from the totals. Invalid traffic is defined as traffic that should not result in the advertiser being charged due to testing, bots, spiders, and other malicious actors. We use proprietary methods of detection to achieve this.
Our first line of defense is the concept of Unique Users. We limit the amount of times an impression or a click is counted within a time period. For instance, if a user were to click an ad in the same email twice within an hour, it would only be counted as one click. Excessive clicks would result in the impression not being counted at all. We have found this to be an effective tool at limiting the impact from bots as well as providing a truer reflection of the value of a click and impression to our advertisers.
Caching by Email Clients
Another factor that can impact reported impressions is how different email clients handle image caching. Many email clients, such as Gmail or Yahoo, may cache images (including tracking pixels) on their servers. When this happens, the impression may only be counted the first time the image is loaded, regardless of how many times a user opens the email. Alternatively, some clients might pre-load images or block them entirely, which can lead to undercounting or overcounting impressions. These caching behaviors vary widely between providers and are outside of our control, so they can contribute to discrepancies when comparing metrics across different platforms.
Google Ad Manager (GAM)
For our Ad server clients, an extra layer of filtering is added by Google Ad Manager (GAM). OpenWeb does not have control over this filtering. However, the methodology in use aligns with OpenWeb right now.
Policy and Service Updates
Updates to Email Service Providers (ESPs), Google Ad Manager (GAM), GDPR, and PII laws can all contribute to seeing different metrics.
Other Factors
- Swapping or updating newsletter templates
- Pausing or turning campaigns on and off
- Updating the frequency of emails delivered to a user per day
Updated about 1 month ago