Interesting service
Unfortunately I don't have any digital files to sell, so I created a test-file.
Some things I've noticed:
1. After clicking "Go to payment page", the browser "Back" button doesn't work.
2. If I update the Available quantity to 0, I can still click "Go to payment page" if I had the public link open in a Tab already. That probably means that if there's only 1 item left, and 2 people open the buy-page at the same time, the item gets sold twice. Is that correct?
3. I can't find the public marketplace.
Fee
The standard fee is 2%. Seller will get: Product price - 2% - Bitcoin network fee.
Depending on the transaction fee you use, this'll be terrible for micropayments. Any chance you'll support Lightning Network in the future? Or is this service meant for more expensive digital files?
Another thought:
This can probably easily be abused by either scammers, or criminals selling for instance illegal photographs. Apart from escrow, maybe you can add a service that verifies the file to be as advertised?
Thank you very much for your comment.
The 3 points you mention will be fix very soon.
The marketplace is still not "public" as I am waiting to have a lots of interesting products first.
I will in the future add a "blue check or something" to confirm the product was verified and is as advertised. (very good idea)
What would be a "good" minimum amount to avoid blockchain spam ? I will read about Lightning Network and see if I can use it.
Again, thank you for taking the time to give a review. I really appreciate it.