Google analytics and ecommerce/cross domain tracking

Question

We have an ecommerce site that tracks users with Google Analytics, currently it tracks e-commerce transactions as goals. Users enter their card details via a third party payment gateway.

The payment gateway allow their templates to be edited so we've added our analytics code to the landing page (enter card details) and success/failure page.

Visitors are never returned to our site by the payment gateway.

I've looked through the documentation but still couldn't find the answer to these two questions:

• Should we have cross domain linking (https://developers.google.com/analytics/devguides/collection/analyticsjs/cross-domain#autolink) set up for this scenario since the payment gateway is a separate domain?
• Partly related to the first question: when we migrate from measuring goals to the enhanced e-commerce tracking are there any special considerations with this setup? Specifically when we actually measure the transaction this will take place on the Payment Gateway (not our site).

Many thanks

Answer 1

Should we have cross domain linking

Yes. Else each user session will be divided in two parts (one on your domain and one on the payment domain - sessions are maintained via the client id from the cookie, and cookies are domain specific). This would inflate the session/user counts, invalidate all "average" metrics and might lose the connection between traffic source and conversion. So by all means implement cross domain tracking properly.

When we migrate from measuring goals to the enhanced e-commerce tracking are there any special considerations with this setup

No. There will be a lot of implementation work for enhanced e-commerce as you need to pass a lot more data to Analytics, but nothing that is specific to cross domain tracking.