How to spot it
- Something is in your basket that you did not put there, usually insurance, priority handling or a charity add-on.
- A consent checkbox is ticked when the page loads.
- The total changed between the product page and the checkout, and no line explains why.
- The generous-sounding default is also the expensive one.
- Unticking is possible but takes a scroll, an expand, or a second page.
Why it works on you
Defaults win because changing one costs attention and most people are spending their attention elsewhere. This is not laziness, it is triage: a default reads as a recommendation, and acting against a recommendation feels like it needs a reason. Designers know the size of the effect precisely, because it is trivial to measure.
What to do
- Read the basket line by line before paying, not the total.
- Compare the price you first saw with the price you are about to pay, and find the difference.
- Assume any pre-ticked box benefits whoever ticked it.
- In the EU and UK, consent for non-essential cookies and marketing cannot be pre-ticked. A ticked box there is not merely rude, it is unlawful.
Where the law stands
Pre-ticked consent is explicitly invalid under the EU General Data Protection Regulation, which requires a clear affirmative act, and the Court of Justice confirmed this for cookies in Planet49 (C-673/17, 2019). Added extras that appear during checkout are addressed by the Consumer Rights Directive, which requires express consent for additional payments. In the United States the FTC treats unauthorised charges as one of its four dark pattern categories.
This is a description of published regulation, not legal advice, and rules in this area have changed more than once. The sources below are the primary ones.