With the move from Universal Analytics to Google Analytics 4, Google have made some changes around both the attribution model as well as how it handles sessions.
Previously, if a user clicked on a link, and then another within 30 minutes, and lastly completed the sale – Google Analytics would see that second click and attribute the sale.
Now, it doesn’t see the second click, or any other clicks within the 30 minute session window. Due to this irregularity, the channel figures you see in UA will be vastly different to GA4.
The difference is stark – one client would potentially cancel an extra 10% of sales! Whilst this might sound good to the finance department, this means publishers will not get paid for their sales – turning them away from your affiliate programme completely. A cashback user would have followed all the directions in the cashback terms & conditions and would be refused cashback. Multiply that one user over the whole programme, and you have a PR disaster waiting to happen.
This is also an accepted point of view from across the industry – The Affiliate & Performance Marketing Association published a guide recently around this issue.
So, by all means use GA4 for your own internal metrics on performance of all online marketing channels, but note that the data must not use for transaction validation purposes.