I actually e-mailed AH asking why they didn't have hats, t- shirts and stuff like that a couple weeks ago. I was told they did have promotional items some time ago but they didn't sell enough to make it worth the hassle of having them available.
I suggested maybe seeing if they could cut some kind of deal with Cafe Press to make hats and t- shirts for them on order. I believe Cafe Press does that sort of thing, although I can't be sure. I've just seen some real small outfits that had promotional items and I couldn't imagine how they could afford to stock them being as small as they were.
I assumed Cafe Press just had designs and would put the item together when ordered.