I have a few fun ideas for designs and logos that I'd like to put on Tshirts (hats, coffee mugs, etc) to sell for a little extra money and helping support good causes. You know those ones where you come up with a design and can put it on stuff and people can order them straight from the website (not actually ordering a ton premade and selling on my own). Looking for decent quality and graphics at decent prices, also good customer service and shipping.
Cafe Press is probably the easiest one to set up. It's user friendly. But you won't make much money. They have a base fee they charge for each item and then you can add to that price what you want. So, expect to make only a couple dollars on each sale.
Zazzle works fairly well. The design software is pretty good, their products are high quality, with great selection on most items. Their shipping, returns, and customer service are excellent.
They are NOT good with crediting the referral fees however, so if you are selling to your barn, for instance, don't count on getting that 15% EVEN if they click on your link (make SURE you use the "star" or RF code EVERY TIME). You still get a royalty percentage, though their prices on some items are a bit too high, so you need to set your percentage very low.
Overall, it's great for stuff for yourself, or stuff for a group (club, barn, team, etc.) if you're doing a few designs or logo items. If you have a lot of designs that you want to sell to the general public, the return is really not worth the time it takes to create and set up your shop. If you're looking to make a few bucks though, it's not the best use of time unless you simply enjoy spending time playing with the designs and software.
This applies to both Cafepress and Zazzle, though Cafepress limits sellers to 10% overall (no referral fee, no bonuses AFAIK, etc.) so the return is even less than Zazzle. The design software used by Cafepress is also not as user-friendly as Zazzle's. I worked with the software and checked out products on both sites before choosing Zazzle for my designs.
Of course, you can always open shops on both sites, particularly if you want access to products offered by one and not the other. There's lots of discussion of the two sites' advantages and disadvantages on Zazzle's forums. CP is often referred to as "that other site" on the forums. .
I've been working on my Zazzle shop for about a year and a half now, and it's fun and extremely annoying at the same time.