Three leads with "Save up to £1035" on trade-in and dates its price rises

The psychology

Why it nudges

A large "up to" saving sets a high anchor, though it depends on the phone traded in. The dated rises are stated next to the price. A cash claim for switching is an incentive. Whether these lift sales for Three is not public.

● Strong evidence · More on anchoring, with sources →

Context

A UK mobile network.

Honest nudge or dark pattern?

Honest nudge

Honest nudge as captured; "up to" savings depend on eligibility not shown on the tile.

Sources: Captured by Nudgeswipe, 16 Oct 2026 (logged out)

Steal this, honestly

Say what you need to trade in to get the top saving.
Keep future prices on the same line, as here.

What to test: "Save up to" vs a typical saving. Measure trade-in completions and complaints.

Next: run it on your product

Apply this with your agent

Take the steps above into your own flow. The prompt carries this teardown, the honest-vs-dark line and the steps.

You are helping me apply a behavioural-design pattern ethically.

Pattern: Three: Three leads with "Save up to £1035" on trade-in and dates its price rises
Bias: Anchoring: An initial number, even an irrelevant one, pulls later estimates towards it.
Why it nudges: A large "up to" saving sets a high anchor, though it depends on the phone traded in. The dated rises are stated next to the price. A cash claim for switching is an incentive. Whether these lift sales for Three is not public.
Our verdict: Honest nudge. Honest nudge as captured; "up to" savings depend on eligibility not shown on the tile.
Source page: https://nudgeswipe.com/examples/three-save-up-to-with-trade-in/ (JSON: https://nudgeswipe.com/api/teardowns/three-save-up-to-with-trade-in.json)

Rules: say a brand "uses" a tactic, never that it "worked"; outcomes are not public unless the company published them; no invented uplift estimates; flag mixed evidence. Honest nudge = true, visible, easy to reverse, and in the user's interest. Dark pattern = hides costs, fakes scarcity or popularity, shames, or makes leaving harder than joining. Quote company-published results as "X reports", with the source link, and don’t generalise them. Don’t cite retracted or failed-to-replicate studies as support (e.g. Ariely & Wertenbroch 2002). Don’t state study figures unless they’re on this page or in a source you can link. If an idea crosses the line, link the matching deceptive.design pattern.

Tasks:
1. Ask me for my product, the flow (URL or screenshots) and the goal.
2. Audit where this pattern already appears, or could, in that flow.
3. Propose 2-3 ethical experiments: hypothesis, variant copy or UI, primary metric, and a guardrail metric (refunds, complaints, cancellations).
4. Flag every dark-pattern risk and say how to stay on the honest side.

Open in ChatGPT Open in Claude Open in Grok Open in Cursor

ChatGPT, Claude, Grok and Cursor open with the prompt filled in (it is also copied, in case the prefill doesn't load). Gemini and Codex don't support prefilled links, so the prompt is copied and the app opens; paste it in.

Sources

Our capture of three.co.uk, 16 Oct 2026
Tversky & Kahneman (1974), Judgment under uncertainty: heuristics and biases. doi.org/10.1126/science.185.4157.1124
Captured by Nudgeswipe, 16 Oct 2026 (logged out): three.co.uk

Three leads with "Save up to £1035" on trade-in and dates its price rises

Why it nudges

Honest nudge

Apply this with your agent

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