We are running a contest on our site. To enter the contest, users click a call to action button on the landing page which takes them to a third-party website to fill out the form (submittable.com) and after they finish the form are re-directed back to a specific thank you page on our site.
The problem is, Google Analytics is attributing all of these users to the third-party form site- which is only a middle step in the funnel- rather than where they originally came from (organic, search, facebook ads). We'd like to be able to measure how many came through the facebook ads and completed a form, despite redirecting to a third-party site as one of the steps.
Is there any way to track users across multiple sessions to attribute where they originally came on successful completion of a goal in GA?