Discounts are a huge draw for people. When there's a sale, they buy an item even if they don't need it. If I don't need something but it's going to be useful in the future and it's on sale, I'm eager to grab it. It's up to us to make life easier by taking advantage of opportunities.
Supposedly, there is a thing where men are more likely to look at red tickets, because they think they are on sale :D