Hmmm, interesting. I have 6,000+ sheets of shrinky dink paper (long story), and aside from sig tags or coin proxies haven't thought of what to do with it all. I might have to send out a couple of "track by emailing me" tags and see what happens.
The referenced "etsy" item "tags" (the part where you are to write the contact information for "tracking") are cardboard. The surprise to me is that cardboard was said to be better than TBs for getting communication about discoveries/moves. The "shrinky dink" attachment is probably not too bad.
I think the ease of the attached tag on these is that the finder instantly sees what he/she is supposed to do with the trackable...no mystery website to navigate.