10 March 2023

Bird leg tagged

What is a click ID?

A click ID outputs a distinct identifier at the time of an ad click, which contains information about the click such as the ad campaign name, creative, keywords, position and so on.

What does a click ID looks like?

If your business uses Meta’s Facebook advertising, Microsoft’s Bing or Google’s Marketing Platform (GMP) eg: SA360, CM360, DV360 or Google Ads and you have enabled auto-tagging in those respective platforms you’ll probably have noticed Destination URLs ending with a gclid, dclid, fbclid or msclkid parameter.

You can learn more about each specific click ID below:

These click IDs are by no means exhaustive and lesser prolific ad platforms will have their own similar versions of the same concept, but Google and Facebook are by far the most prevalent across the web due to these companies extensive ad network and user reach.

What are some problems associated with click IDs?

A click ID can allow the platform that generated the click ID to associate a click with a specific user identity, especially when that user is signed into that platform e.g. a user who is logged into their Facebook or Google account.

Apple’s iOS 14.5 update

On April 26th 2021, Apple released the iOS 14.5 update which contained the app tracking transparency (ATT) framework. This framework specifically took aim at click IDs because of their ability to be associated with an individual user. This functionality of click IDs was emphasised as a problem by Apple (prior to the iOS update) in their post about PCM (Private Click Measurement).

Apple’s primary motivation was clearly to restrict click IDs to prevent large tech firms such as Google and Facebook from being able to attribute the data of an ad click/conversion journey back to a single user as part of a broader scale cross-site tracking framework.

How are advertising vendors adapting to Apple’s update?

Advertising companies were quick to respond to the new challenge imposed by the App tracking transparency framework. Their solution was to send hashed customer data points back to their platforms when a conversion takes place as an alternative identifier to a click ID. For example hashing a customers email address or phone number which are distinct identifiers on a per user basis:

How does this solution impact conversion attribution?

In various tests we’ve run to date with clients, we have found uplift in attributable conversions starting as low as 10% through to 40%+ in the case of The Smith Family case study. Meaning without the use of a click ID alternative solution, advertisers may lose significant visibility into campaign attribution and effectiveness.

What does the future hold for these click ID alternatives?

At this point Apple has not created a solution to prevent hashed customer data being sent to these platforms and may not be able to do anything about it in future, especially when the data may be sent via APIs outside of the purview of Apple’s Safari Browser or iOS operating systems.

Therefore the viability of this alternative to click IDs and using hashed customer data being at risk in future depends more on privacy legislation than technological solutions.

You can refer to this summary piece on EU GDPR and CCPA and their take on hashed customer data. However in Australia we are still waiting on the outcome of the 1989 Privacy Act review and subsequent legislative updates.

Until then, we’re recommending our clients to adopt click ID alternatives to restore campaign attribution abilities where applicable.

About Gavin Doolan

Gavin Doolan specialises in web analytics technology and integration. In his spare time, he enjoys restoring vintage cars, gardening, spending time with the family and walking his dog, Datsun.