Why a third price you'll never buy makes you spend more

Picture a coffee shop with just two sizes: a small latte at $3 and a large at $5. Plenty of people, doing quick mental math, pick the small. Now the shop quietly adds a medium at $4.50 — barely smaller than the large but almost the same price. Suddenly the large looks like a steal, and sales of it jump. The medium itself rarely sells; that was never its job.

That medium is a decoy: an option engineered not to be chosen, but to reshape how you judge everything next to it. On its own, 'is $5 worth it for a large?' is a hard, abstract question. Put a slightly-worse-for-nearly-the-same-price option beside it, and your brain grabs the easy comparison instead — large vs. medium — where the large obviously wins. You feel like you found a bargain, and you trade up.

Marketers call this asymmetric dominance: the decoy is clearly worse than the option they want you to buy (the target), yet not worse than every alternative. Because people are far better at comparing two things than at valuing one thing alone, that single lopsided comparison does the persuading. Watch for it the next time a pricing page, a ticket tier, or a combo menu offers a middle choice that seems oddly pointless — it's usually working on the option right next to it, not on you directly.