On Zoom you have the option to create different tracking links for the same sign up form and then as you have a bunch of people begin to register for a webinar lets say, you can easily see where your traffic came from and where it didnt. I think for the fundraise feature where it says "Share you link" there should be a tracking link option where people can create a link for their Website, a link for their emails, a link for different social media channels and so on. This way you dont have users fall off with the extra step of the referral source feature and you also don't have to figure out the UTM source code stuff if you are not familiar with it. Helps NPO's work better and faster