Using browser exploits to steal commissions from affiliate links without even the user knowing.

Then if you used PayPal checkout, they would also “find” you discounts but swap them out with lower ones and pocket the difference. For example you buy something for $10 and they find a 30% off coupon, but tell you it’s a 10% off coupon. You go to checkout with PayPal and they charge your card $9 but only pay the merchant $7 and pocket the other $2.