Can I track the conversion rate for the returning visitors coming up from follow-up campaigns? Actually this is a good question. Yes, we can!
You see, this is tricky. You may think that Google Analytics will do it, but that’s not entirely true. First of all GA, records users’ sessions by client id. Thus if you send one email today as part of CAMPAIGN 1, and you tag the links inside that email, GA will record the data for the visitors that click the tagged link. Then you decide to send a follow-up email campaign tomorrow, let’s call it FOLLOW-UP 1. You also will tag the links accordingly, but here the problem arises. If a visitor that priory entered the website coming from CAMPAIGN 1, uses a new browser / new device to open the follow-up email and clicks the links, GA counts him as a new unique visitor. The cookie saved in the old browser won’t pass between the sessions. You will be able to track only the returning visitors that use the same browser. That’s a shame!