When you're looking for an extra discount on an order you're placing online, try leaving your cart alone for a day. Companies sometimes email discounts to entice you back.
Photo by Guttorm Flatabø
These campaigns are part of a marketing tactic called "abandoned cart recovery". Online retailers can obviously track your cart as you're shopping, but if you leave the site and don't finish your order, they're motivated to get you back. If you have an email address attached to the account, some retailers will elect to email a reminder that may include a discount.
Of course, not all abandoned cart tactics include a discount. Some sites will simply email you a reminder and avoid rewarding abandonment. Nonetheless, for non-urgent purchases, it's worth trying.