As far as I know i.Materialize has no system for Affiliate marketing payments (neither does the competition BTW). Meaning no way for a designer to automatically pay somebody willing to promote their products. I think this is a huge missed opportunity for designers and i.Materialize. There are a lot of people out there that have no idea what i.Materializeis, so to sell to these people, the marketing can only be done personally through social marketing or you have to pay for it. Affiliate marketing allows designers to give a re-seller an incentive (through partial profits) for promoting or selling your products (a payment system that automatically splits payments based on a percentage of the profit). This would greatly increase the sales of products, meaning more money for designers and of course i.Materialize. Ya it would mean another 3% to PayPal, but it opens up huge possibilities. If anyone has a clever way to circumvent this problem I am all ears.
In my experience trying to build an ebay site to sell printed rings, with all the different variants, it just becomes too cumbersome to have an external site selling. It would be much easier to link to the store.