Reminds me of (the now defunct) Startup Schwag ( http://www.startupschwag.com/ ). I'm a sucker for stickers and tshirts with a cool company logo so it sounds awesome. I would take a look at what Startup Schwag was doing - if I recall you got a 'goodie bag' each month that had a shirt and some stickers, buttons, pens, etc.
For now, we're just looking to do a limited-time offer from 25 startups (already have 5+ great startups committed) as a scrappy way to keep on bootstrapping our startup.