As part of our migration away from Google Analytics to Amplitude as our primary tool for websites/ apps I'm doing some validation of marketing channel/ campaign data from UTM parameters.
In our "utm_medium" parameter we have a value of "organic"; this has a value of 6,791 sessions in Amplitude for a particular time period....but over in Google Analytics it's vastly higher at 20,803 for the same time period. I've set saveParamsReferrerOncePerSession to false in our Amplitude tags in GTM, and also left unsetParamsReferrerOnNewSession set to false....this configuration I believe should reflect the Google Analytics default "last non-direct click" attribution, so I'm struggling to understand why Amplitude is reporting so much lower?
One thing that did cross my mind is that I don't see utm_medium = organic passed in the URL query string for all clicks from Google organic results for our site. Which suggests to me, perhaps, that Google Analytics might have some automatic config somewhere to be able to assign utm_medium = organic even when that query parameter is absent in this scenario. If that is indeed the case this would explain the drastically different numbers...in which case how can we configure Amplitude to replicate this?