Dark Patterns Part 2: Hidden Costs

Posted by Mike O'Brien on September 23, 2025 in Consumer Behaviour, Customer Experience, Customer Insight, Customer Journey, ecommerce, Postcards from the digital frontier | Leave a comment

You’ve chosen the product(s) – think Amazon’s upsell suggestions. You’ve entered your details. You’re seconds from hitting “buy.”
Then – the sting: extra fees revealed only at checkout.

This is drip pricing or hidden costs. Airlines perfected it. Hotels followed. Now, it’s everywhere from concert tickets to clothing.

Why it works

Behavioural economics calls this the sunk cost effect. Once people have invested time and effort, they’re reluctant to abandon the process, even if the price jumps. You’ve already spent 10 minutes filling in forms – why start over elsewhere?

When it crosses the line

Adding delivery charges or booking fees isn’t inherently wrong. But it becomes a dark pattern when:

• Costs are concealed until the final step.
• Essential extras (like taxes or compulsory service fees) are disguised as “options.”
• Total price transparency is deliberately obscured to win the click on comparison sites.

The CMA flagged hidden fees as a major concern in its 2022 research. In the airline sector, the difference between headline and final prices was sometimes more than 30%.

The hidden cost (for brands)

Short-term gain is obvious – customers push through. But the long-term damage is harder to measure and more corrosive:

• Abandoned baskets skyrocket once people feel “tricked.”
• Trust evaporates, and with it, repeat purchase potential.
• Brand reputation suffers – one viral post about hidden charges can undo months of marketing spend.

The brighter alternative

The solution is simple: total price upfront.

• Show the real cost from the start, even if it looks higher than competitors.
• Use “all-in” pricing as a trust signal.
• Make add-ons genuinely optional, not sneakily essential.

Because in a world of comparison sites and review culture, clarity isn’t just ethical – it’s a differentiator. The brands that show everything up front are the ones customers return to.

Fact Check

The CMA’s 2022 review of online choice architecture found that hidden fees (also known as “drip pricing”) were among the most common harmful practices, particularly in travel and hospitality. The regulator has since pushed for all-in pricing transparency across digital platforms.

Next in the Series: Part 3 – Sneaky Defaults