Apple recently announced changes to the way Safari browser on Desktop & Mobile will handle 3rd party cookies. The change most directly targets DSPs, programmatic display networks & data aggregators - not Google Adwords conversion tracking. However, Google Adwords conversion tracking is affected.
Moving forward Safari is reducing the efficacy of 3rd party cookies so that they can only be used for remarketing and conversion tracking within the first 24 hours. After that they are retained for login purposes only, and after 30 days they are purged.
This means that unless a user converts within 24 hours of clicking an Adwords ad then conversion attribution will be lost. The standard measurement timeline is 30 days after a click.
Several common ad technologies use 3rd party cookies to track and are affected. They are:
To respond to this change Google developed a new Adwords pixel that needs to be implement on site. Google has also updated the way Google Analytics places cookies and this does not require any changes to your site. Facebook tracking continues unaffected.
We'll be reaching out to individual clients with instructions on how to implement the new Adwords pixel to ensure conversions are tracked properly and that Adwords remarketing continues unscathed.