Williams-Sonoma added a pricier bread maker. Almost nobody bought it. The cheaper one nearly doubled.

Add a $429 nobody buys, and the unchanged $279 beside it suddenly looks like the smart pick. The priciest item on the shelf is there to sell the one next to it.: Pro · $429 · Standard · $279

It was never meant to sell. On its own, the original looked like a splurge. Next to a costlier twin, it suddenly read as the sensible middle. The shopper's reference point quietly moved. This is the decoy effect: one option exists only to flatter another. By some accounts, that nudge roughly doubled the original's sales.

Sometimes the priciest item on the shelf is there to sell the one beside it.