Keep in mind Etsy only takes a cut, and it's close to 8%. If I sell a $100 item they take about 7% in transaction fees. Then there's merchant fees for payment processing. I'm sure Etsy take a cut of them, and they are about 3%, so assuming they get 1 point of that their total take is 8%.

In comparison Ebay w/ PayPal merchant fees is a few points higher at about 14%. Which if you're selling high volume low margin race-to-bottom Alibaba junk then the extra 3-4% profit explains why Etsy's loosing of seller restrictions has attracted so much junk. The bank payment processing probably isn't doing an even split, so I would guess that Etsy's take really is right about 8% of seller revenue.