The reason that so many online and brick-and-mortar stores have sales is, unsurprisingly, that they work. The rational approach may be to prefer low, constant

The reason that so many online and brick-and-mortar stores have sales is, unsurprisingly, that they work. The rational approach may be to prefer low, constant prices all the time. But neither the market nor consumers are rational. Look at JCPenney, and their "no sales, just everyday low prices" policy. Rationally, all their prices were slashed, and there was no need to wait for a sale or find a coupon. What actually happened is that no one felt urgency to go to the store, or excitement that they were getting a discount. This policy tanked, and has since been dropped. I know it may feel spammy or artificial when e.g. Newegg is constantly running "amazing, once in a lifetime sales!!!", but fundamentally, these work. For every "rational" person who waits a year for free shipping, or drops their cart out of ennui over price volatility, there are 10 people who visit the site due to a promotion, and take out their credit card because of a coupon they have. Trust me, I work in the retail space, and retailers measure the effects of promotions very carefully. These things work, and retailers must embrace them or lose money/market share.