Sometimes, we have the uncontrollable habit of buying things we dont actually need, especially when items are on sale. We stock up on things that are on sale thinking that we are saving. At first thought, it seems we are, but on second thought, we are actually losing. Foodstuffs get spoiled. Clothes go out of fashion. Appliances warranties expire even before they are used. Sometimes, they become defective due to prolonged storage. And new models are introduced which makes what you have on hand, obsolete or phased out. This might probably be the reason why they are on sale. If you notice, most electronic appliances are expensive the first time they are introduced and they become cheaper in time.
We stock up on things thinking that a similar opportunity might not come our way the next time. I hate to say this but probably some products are excessively produced on purpose, to be put up on sale if not completely sold while regularly priced. To some producers, its cheaper to sell at cost or minimum profit than to keep under storage, not to mention expiration dates. This is also one way to promote a product. You see, when people know that a certain product sometimes goes on sale, they always have the product on mind. Its free advertisement at its best. The product makers dont lose money anyway. On the contrary, they make money.