Selling your branded t-shirt or baseball cap makes sense when your publishing project has a strong brand, a powerful message or an issue that it stands behind.
Why would people shell out USD $20 or more to buy a branded t-shirt promoting a web site? If a bold tagline spells out a strong message or slogan about something of which many are passionate, readers want to support the cause by wearing them.
I think this works effectively where a) the personal brand is good enough to create a desire in readers to "stand" for it (few bloggers or news sites have this kind of charisma, but I people like Joi Ito or Howard Rheingold most likely can command some of this), or b) the author or blog / site stands for something clearly identifiable. It may be an overarching mission or a number of changing issues that make effective marketing themes for such products.
CafePress offers an extensive catalog of shorts, caps, calendars, mugs with over 80 customizable merchandise products waiting for your logo and tagline to be printed on them. CafePress provides the raw merchandise that you can customize by uploading your artwork and interactively adjusting it on through its online command center.
While CafePress charges a base cost for the material (e.g.: USD $13.99 base price for T-shirts), you can price your branded merchandise however you like and CafePress dutifully manages the transaction, payment, shipment and your monthly payments for your hard-earned commissions. In the process CafePress, also creates a full web-based shopping center that can be customized to match your Web site's design.
