Last-click attribution best practices

Resolving last-click discrepancies

If you're using Google Analytics for your reporting, keep in mind that Criteo and your other reports may not always align. Discrepancies of up to 30% may occur.

There are a few things you can do to minimize discrepancies. First, make sure that you're looking at the same scope:

  1. Ensure that your date range, timezone, and currency are set up the same way in Criteo and Google Analytics. Note that timezone changes within the Analytics module of Criteo only apply to your reporting, whereas Google's timezone applies across your global settings (not only reporting). We recommend changing the timezone in Criteo's Analytics module rather than in Google Analytics
  2. By default, Google's attribution model is last non-direct click. However, some Google Analytics reports use other attribution models. Check that you're looking at last non-direct click metric in Google Analytics and not last interaction
  3. Ensure your ad URLs have UTM tracking parameters and that your transaction IDs are unique (see here)

Keep in mind that some discrepancies will be a result of the different methods to compute last click.

Criteo is not capturing all the traffic sources

Criteo uses UTM parameters to identify the last-click channel and attributes a conversion to the most recent Criteo ad clicked among all channels with a UTM.

Google Analytics attributes based on the most recent click among all of your marketing channels such as emails, organic research, and AdWords.

If you’re using a channel that doesn’t support utm_source such as Google CPC, organic search, or paid media, they won’t be captured by Criteo.

Google captures last clicks older than 30 days

Criteo takes credit for a sale if it appears within 30 days following the last click. Google Analytics may take credit for a sale up to 180 days following the last click.

Different data processing latency

Criteo's data processing latency is 12 hours maximum. Google's latency may be between 24 and 48 hours.

Your website’s referral policy 

To enable last-click attribution within Management Center, you need to actively set a referral policy for your website  which is supporting UTM processing to Criteo. If no explicit referral policy is set, the option of last-click attribution in Analytics in Management Center will not be available as Criteo will miss a significant share of your website traffic. This will lead to inaccurate last-click attribution in Management Center. 

To collect UTM parameters, Criteo processes the referrer URL when a user is entering the website. When no referral policy is set, the default settings in the browser will apply. 

Google Chrome changed the default setting in August 2020 with the release of Chrome 85 to “strict-origin-when-origin”, which cuts off any additional parameters beyond the website’s origin (including UTM-parameter). It is expected that more browsers will change to “strict-origin-when-origin” as their default setting in the future.

Chrome still offers the possibility of other referral policy settings which will provide the necessary information for Criteo to collect data for your last-click attribution. For the best experience with your Criteo campaigns, we recommend going into your settings and selecting a referral policy that supports UTM processing to Criteo.  

We recommend “no-referrer-when-downgrade” where the origin, path, and query strings of the URL are sent as a referrer and the protocol security level stays the same or improves (https→https; http→https). 

For more information on referrer settings, please visit Mozilla’s developer page or Web Developer: Referrer-Policy Best Practices.

Note: Measurement in Google Analytics tracking is not impacted by a browser’s HTTP referrer policy. This is because Google Analytics is using its own Document Referrer field. More information here.