3rd party are affiliate sales. They are just listed as 3rd party in our royalty reports. They could be any associate that shared your product or from Zazzle emails or promotions, and are unrelated to design transfers in any way. I don't think we pay the whole 15% to the affiliate. Zazzle pays a portion and we pay a portion, but I can't find that information in the help section so I may be wrong about that.
Design transfers use your default royalty so if you have that set at 10%, then you will get 10% on the sale. I keep my default royalty at my highest store royalty rate so that I get the royalty I want on any sale. That way if they transfer a design from a postcard that I keep at a lower royalty rate, to a poster that I keep at a higher royalty rate I will still get my higher royalty and not one of the lower rates. I have also made sales from transfers where it has worked the opposite way, but I have no problem selling all my items at the highest royalty if someone wants to make a design transfer. I have had quite a few sales from transfers and I love having that option open so that I can sell designs on anything the customer wants without having to put the design on every item on Zazzle.
If there are products that you do not want to sell your designs on at all or you just don't want your designs transferred, then turning off design transfer is definitely the way to go. If it is a matter of you not getting the royalty rate that you would have wanted, raise your default royalty to the amount you feel comfortable selling anything at. It is just a personal choice on how you want to run your shop and we all do it differently.
