I just posted a new product on Tindie. It's a tiny, bare board that is cheap and small enough for me to offer free shipping.
As a promotion I was planning to give away the first batch for 100% free using a discount code. The product also has a free shipping option, so all a user would have to do is fill out their address and hit submit. Or so I thought.
It looks like Tindie does not support or have any way to handle orders where the grand total is $0.00. It still prompts the customer to enter CC info, but even if they do, the order will never process because it has no dollar amount.
My present best workaround is to charge some small token fee ($0.50) for what used to be my "free" shipping option. But that's kind of a bummer.