Watch rewards is a discount rewards incentive used to encourage interaction between you and other users, not a well of free money to be tapped at the expense of the app. You cannot, at any point, use your watch rewards to pay for 100% of any purchase, there is a % or dollar amount limit that is displayed on your current purchase number under watch rewards on your profile. The discount off of your current purchase is based on whichever number is smaller, the % off or the dollar amount. So if you have 80% off up to $100, that means you can put in up to $125 total purchase price into your cart, and still get your full 80% off, but if you go past $125, you’ll cap out at the $100 discount, but your % off will slowly start to fall as you add to your cart