Staples takes $20 off orders of $100 or more via this link. (Click "redeem now" to generate a unique coupon code.) Plus, most orders qualify for free shipping. That beats our mention from three days ago (when we saw $10 off $100) and it's one of the best online dollar-off coupons we've seen from Staples so far this year. (We saw $5 off tech accessory orders of $25 or more last month.) Deal ends August 31.
Update: Link updated. You don't need to run the application; just click "cancel" and the coupon generator will load.