I want to join Associates Program and sell e.g. T-shirts with the Superman logo. Where can I get photos with these T-shirts to put on my Instagram? Of course with links to Zazzle official store.
I have the skills and I would do it, but Zazzle doesn’t allow it directly,so I don’t want to have problems with the license 
@msz you can, of course, join the Zazzle Associates program to promote Superman as an affiliate, but DC Comics has a presence on Zazzle and no fan merch is permitted. https://www.zazzle.com/store/dccomics
You will have to screenshot the product image from the official Superman store (or whatever product you want to promote as an affiliate) on Zazzle and then add that to your social media with the link back to the product.
I wanted to redirect to this store. But I want to use their photos in my posts, since I can’t link to them on Instagram. Too bad. Thanks for reply.
I know about this method, but will no one from zazzle or dc prosecute me for it?
No. Not as long as you are linking back to the product that is in the screenshot and giving proper credit. You basically get permission when you become an affiliate. Make sure you disclose that it is an affiliate link and all that jazz.