Hopper's "Swipe to Book Flight" slider sits at the center of a phone screen. Two pre-selected fees, a Tip and VIP Support, sit below it, past the bottom edge of view. The checkout screen broke the brand promise before the user could scroll down to find it.

"Be transparent and the trust will follow." Most operators who sell anything online have heard some version of this. It is the most repeated piece of brand advice in the market. Hopper built its brand around three words: "no hidden fees." The checkout page hid two of them below the one button users needed to press. Users swiped. They paid both fees. They never scrolled.

The advice is not wrong in spirit. It is wrong at the level of design. And design is where money changes hands.

The research on this is clear. In 2003, behavioral scientists Eric Johnson and Daniel Goldstein tested organ donation forms with a single change: opt-in versus opt-out. Different people. Same stakes. One checkbox. The opt-in form got 42 percent. The opt-out form got 82 percent. A 2025 study in Scientific Reports confirmed the finding still holds across 317 participants, with 38 to 39 percent choosing whatever option was pre-selected, well above the 25 percent you would expect from a four-option choice.

The term is the default effect. It works through three forces. First, effort: switching takes a click most people skip. Second, implied endorsement: if someone pre-selected it, it must be the right choice. Third, reference dependence: the pre-set option feels like something you already own, and losing it feels like a cost. Each force nudges the buyer toward a fee they did not actively choose.

"Be transparent" does not fail people. It fails the system they are trying to run. The advice tells you what to say on your brand page. It says nothing about what your checkout page does with a pre-checked box.

That gap matters more than most operators think. The problem is not dishonesty. The problem is that a claim on one page does not override a design choice on another page. Your checkout flow is a separate document from your About page. Almost no operator reads them side by side. And the buyer only sees the second one at the point where money leaves their account.

Hopper did not guess about the gap. They measured it. In 2018, internal A/B tests showed that 15 percent of users paid the Tip fee when it was shown and unselected. Twenty-five percent paid when it was shown and pre-selected. Seventy-five percent paid when it was hidden and pre-selected.

Five to one. The company saw the split and shipped the version that hid the toggle.

An employee wrote in an internal message: "To me, the problem here is that we're tricking users." The concern was raised. The data confirmed it. The company shipped the design anyway. Between 2021 and 2023, Hopper collected roughly $18 million in Tip fees and $67.6 million in VIP Support fees. That is $85.6 million from charges most users never knew they agreed to. The FTC settlement cost $35 million.

Most people treat this as a character problem. It is a system flaw. The brand page said one thing. The checkout page did another. Two documents, one company, and nobody compared them until a regulator did.

Transparency is not a value you state. It is a layout you ship. Once that is clear, three moves follow from it.

Open your own checkout page on a phone. Do not tap anything. Look at what shows before you scroll. Every fee, every add-on, every pre-selected box below the fold is hidden in practice. It does not matter what your FAQ says. It does not matter what your terms page explains. The scroll line is the honesty line. This is the move that asks the most of you, because you built that page and you will want to defend it.

If an add-on is worth the price, buyers will turn it on. If they will not, the add-on was not selling. It was hiding. The three forces of the default effect, effort, endorsement, and the sense of loss, were doing the work your product could not do on its own. Remove them. See what holds up without the crutch.

Print your sales page. Print your checkout flow. Set them side by side on a table. Every claim on the first page that the second page breaks is a gap. Your buyer will find it. Or a regulator will. Hopper's gap between the marketing copy and the checkout design sat open for years. It cost them a federal complaint and $35 million.

Running this for 30 days does something the advice never did:

You see which add-ons survive an honest default. Those are real products with real demand. You find the exact spot where your copy says one thing and your page ships another. You learn the dollar figure that depended on a pre-checked box and nothing else. And you find out whether your buyers trust the flow or just fail to notice the fee. That difference is worth knowing before someone else points it out.

At the end of 30 days, ask three things.

→ What moved the number when the default was off?
→ What looked like revenue but left no trace once the box was unchecked?
→ What friction showed up more than once when buyers saw the full price up front?

That is the difference between advice that sounds right and a system that proves itself.

Your brand page is the story you tell. Your checkout screen is the document your buyer reads. Hopper told one story and shipped another. The gap sat open until the FTC closed it for them. You do not need a regulator to read your own two pages side by side.