It's an interesting methodology. Some thoughts: (1) 12 times is way too low for number of wears. I'm probably extreme, but I've got tech shirts that could appl

It's an interesting methodology. Some thoughts: (1) 12 times is way too low for number of wears. I'm probably extreme, but I've got tech shirts that could apply for a drivers license; I've easily worn some of them hundreds of times -- let's say every other week for the last 500+ weeks. (The older shirts are too worn thin/ragged to wear in public any more though.) (2) I'm not sure CTR is going to be as high as an explicit ad. Clicking a link is a fairly low barrier, and still only gets a 0.14% conversion. CPC is probably the wrong model to apply; you might want to look at it as traditional advertising and apply a CPM. For what it's worth, I'd bet that your conversion rate would be higher than average since the visitor has already qualified themselves somewhat more than just a casual clickthrough. (3) For all of the times I've worn those tech shirts, I can only recall a couple of times when someone has actually talked to me about one of the shirts. Once (a nice polo shirt with embroidered logo) I was asked if I worked for the company (which was somewhat well known) -- the answer was no. The other time was when a fan of the by-then defunct company mentioned on the shirt remarked that it was too bad the company had imploded. (4) I've gotten free t-shirts that required very little engagement on my part with the company. E.g. rackspace sent me a shirt several years ago I think just for answering a survey; I've never been a customer. Definitely consider giving shirts to people who can actually talk about you if someone does ask about your company. IOW, the CPM on a "talking billboard" is worth more than on a static billboard.