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3rd party tags impressions & clicks discrepancy problem • TCF 2.0

3rd party tags impressions & clicks discrepancy problem • TCF 2.0

Wojtek Andrzejczak
Wojtek Andrzejczak
3rd party tags impressions & clicks...

TCF 2.0 as a new source of problems with the campaign discrepancies for 3rd party tags used in the digital campaigns.

What is TCF 2.0?

Shortly, TCF became a privacy standard to communicate between websites, ad servers if a user is willing to be tracked and share his information for marketing purposes.

How TCF 2.0 works?

Each website should ask the user if he agrees to be tracked for marketing purposes. If he agrees, then marketers can collect user data and deliver retargeting campaigns to him.

The user choice is to send each ad unit on the website and then transmitted to every connected 3rd party ad server delivering ads to the user.

3rd party tags in Google CM360

Often, publishers use 3rd party tags to deliver ads, and sometimes ads are embedded with additional nested levels.
For example, you use the 3rd party CM360 INS tag in the other 3rd party CM360 account.
GRPR’s macros included in the INS tags represent TCF 2.0 standards.

Google Campaign Manager 360 / Custom Display creative / 3rd party HTML tag
Google Campaign Manager 360 / Custom Display creative / 3rd party HTML tag

Campaign impressions and clicks discrepancy problem

I’ve noticed an increasing amount of discrepancies in the delivered impressions and clicks between our and the clients CM360. The discrepancy is reported at around 70-80%.

Switching 3rd party tags to ZIP files with original HTML5 files and attaching Impression and Click tracking events (client’s Ad Tracking ads) also did not help.

Problem identified

After checking multiple aspects of the setup, the last thing left was checking if removing TCF 2.0 macros from both INS tags and Ad Tracking events (impression + click) will help.

What a surprise, suddenly all numbers matched, discrepancies disappeared.


Simply, when “${GDPR}” does not contain any value (is empty) then, Google collets everything like it always did.

But, as soon as you pass a value like 0 or 1, Google respects this value. 

If you pass the wrong value, then Google assumes you set “0”, so the user does not want to be tracked.


Also GDPR_CONSENT_755 and ADDTL_CONSENT values might play a huge role as a troublemaker.



Websites and Apps usually contain multiple ad units. It can happen that some of them have passed wrong values, which might affect the reporting problems, as described above.

Unfortunately, it is impossible to identify which ad units on the website/app are causing the problem.

It also seems that the implementation of the TCF 2.0 is still not entirely done as we’d like to see.

Of course, removing TCF 2.0 macros is not a good idea, but it is good to check if it is a cause of the discrepancies.


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Show Comments (1)


  • Anonymous

    Was CM360 70-80% higher or the third party platform? Thanks for sharing.

    • Article Author
    • Reply

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