Dark Patterns · principle
Hidden Costs
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Revealing mandatory fees only after the user has invested effort — drip pricing. The advertised number wins the comparison; the real number appears once sunk-cost makes abandoning feel expensive. Total cost belongs where the decision happens.
Where it comes from
Drip pricing predates the web — the car-lot "documentation fee" and the ticket-window "service charge" ran the same play. Brignull's taxonomy formalised it for interfaces, and India's CCPA Guidelines (2023) name "Drip Pricing" explicitly, alongside Basket Sneaking. The economics rely on sunk-cost bias: five minutes into checkout, ₹300 in surprise fees feels cheaper than starting over.
Origin: Car-lot documentation fees; CCPA Guidelines 2023 (Drip Pricing)
In the wild
- Food delivery & ticketing
Platform, handling and "convenience" fees materialise at the last step — the ₹499 that pays like ₹798.
- Hotels
"Resort fees" worth a third of the room price surface on the confirmation screen.
- Honest flight search
Results that show tax-inclusive totals per card prove comparison and honesty can coexist.
Further reading
Don't just read it — feel it.
Play the 3-minute game and let your own reactions prove the law.
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