Spreadshirt recently launched a new section on their site for affiliates. The Spreadshirt affiliate program is centered around their Custom Product Designer where users can create their own custom t-shirt. They offer a minimum 20% commission on referred sales (up to 30% for high performers).
You can join the Spreadshirt affiliate program at Shareasale or Commission Junction (CJ). I am a Spreadshirt affiliate through Shareasale and have not spent a lot of time with CJ. But I did just sign up on CJ also to check out their datafeed and could only find products for the Germany based affiliate program. Looks like they have 400+ t-shirts for those who have German language sites…..Hopefully they will add some for the U.S. based users AND add them by subject or theme. Having a feed of 400 random shirts is ok but I would rather have a feed of 400 shirts related to a very specific subject. Along the same lines, there are no subject specific landing pages set up for affiliates which makes it difficult for an affiliate to drive targetted traffic. They have lots of great products but they are all hiding in stores that the majority of people will never see with the exception of the store owner. They do have the Spreadshirt VBG/Ubershop but as I have mentioned before is a very limited solution to finding unique products are Spreadshirt.
For more info check out the Spreadshirt affiliate program FAQ for those who have unanswered questions or to sign up.