That’s a fair read of the post. Codes don’t stack: if auto-apply is on and someone arrives with a different code, the larger discount is the one that applies, and it’s still one code per product. PPP versus a code is the same rule — the buyer gets the better of the two, and the only way to force the code is to turn PPP off for everyone. On the Discover side, the documented fee line stays the flat 30% (processing included); there isn’t a published formula for the exact net after a code, so the sales CSV is the right check rather than invented math.
StackShortlist
Proof Over Promises.
The note that discounts never stack, and that Gumroad applies whichever is larger when auto apply meets a different code, saves sellers from promising a combo that can't happen. Same with PPP versus a code, since forcing the code means turning PPP off for everyone. Pointing people to their own CSV for the exact net on a discounted Discover sale, instead of inventing the math, is the honest move.