We're currently running A/B URL redirect tests using Google Optimize. When a user is triggered to be tested, Optimize cookies this session with UTM_EXPID (Experiment ID for the test) and UTM_referrer (Previous page before the experiment). In the event that the referring page is not the original landing page with UTM source/medium/etc., the UTM referrer in the Optimize test is simply the previous page.
Google Analytics tracks these correctly coming from the original source /medium; however, Marketo doesn't create the lead until after a form is submitted which means that the only UTMs it sees are the ones from the Optimize-created page (utm_expid and utm_referrer without source/medium/etc.) Essentially, for most leads, there is no UTM whatsoever because Optimize only creates expid and referrer.
Is there a workaround for this? Marketo correctly attributes the "Original Source Info" to the original landing page, but without any UTMs. Being that the Munchkin script does create/start tracking/cookies from the first landing page - which contains the original UTMs - is there a way to capture those UTMs? Would adding utm_expid and utm_referrer as hidden fields help the capturing of any missing UTMs instead of the previous page UTMs after form submit?
To be clear: Google Analytics does pick up all UTMs correctly without misattributing anything. It's only that Marketo passes off the UTMs after form submit, and I guess it only collects the Optimize UTMs when a user is tested, and not from the original landing page.
Also, the utm_referrer from Optimize will contain all original UTMs only if the previous page was the LP, but the URL is encoded with %26 (ampersand sign) but it doesn't show up in the url as "&".
A bit technical and may be confusing - I'd be happy to provide more information to clear things up.