Looking at this from a numbers game, as Etsy is probably doing, this is a guaranteed money source for them. All they have to do is claim they are running intern

Looking at this from a numbers game, as Etsy is probably doing, this is a guaranteed money source for them. All they have to do is claim they are running internet ads for your product. Whether that ad worked or the sale just happened based on normal Etsy traffic, is probably not disclosed. Hence Etsy has 100% control of the information and therefore can bet, let's say $1M per day towards this, but on the flip side, can guarantee that a 12% fee increase (for the stores that will be required to pay it) will already be $2M per day. My numbers are fake but you get the gist.