ValidationBy Day Zero
Fake door test vs. pre-sale: how to test demand with real money
A fake door test shows a button for a product that doesn't exist yet and counts the clicks. A pre-sale asks people to commit a card. Clicks measure curiosity; a pledge tells you who will pay.
In short
- A fake door test, also called a smoke test or painted door test, counts clicks on an offer that isn't real yet.
- It's quick and cheap for comparing messages and prices, but a click costs the visitor nothing.
- A pre-sale is the real door: people commit a card for something that will exist.
- On Day Zero the card is saved, not charged, until the founder opens access, so the test is real and low-risk for backers.
A fake door test puts an offer in front of people before the product exists: a pricing page, a Buy button, an ad, a new item in a menu. When someone clicks, they learn it isn't ready yet, usually with a form to join a waitlist. The number of clicks is the signal. A pre-sale goes one step further and asks people to commit money.
What a fake door test is good for
- Comparing headlines, features or prices against each other.
- Checking whether anyone notices a new feature before you build it.
- Getting a first read in days, with a landing page and a small ad budget.
Where it falls short
- A click is free, so it measures curiosity, the same as a waitlist signup.
- Plenty of people who click Buy would stop at the card form. A fake door never gets that far.
- Visitors who hit the fake door can feel tricked, especially the ones who wanted the product.
- You end up with a list of emails, not customers.
| Fake door test | Pre-sale | |
|---|---|---|
| What people do | Click a button | Commit a card |
| What it measures | Interest in an offer | Willingness to pay |
| What it costs them | Nothing | The price, if it goes ahead |
| What you end up with | A click rate and a waitlist | Paying customers |
| Best for | Comparing messages and prices | Deciding whether to build |
Run fake doors honestly
If you run one, tell people straight away that the product isn't ready, what you're building and how they'll hear when it is. Don't ask for card details for something you haven't decided to build, and don't leave a fake door up for months.
From a fake door to a real one
- Use fake doors, or plain landing pages, to pick the message and the price that get the most interest.
- Build the smallest thing you can show: a prototype, a clickable mockup or a demo video.
- Open a limited pre-sale to the people who clicked and joined the list.
- Make it all or nothing, and charge only when the product is usable, so committing is easy.
If enough people commit, you have your first customers and a reason to build. If not, nobody pays, and you found out before writing the code. More in how to validate a SaaS idea before you build it.
The real door on Day Zero
Day Zero is a pre-sale for software before launch. You list your product with a prototype or mockup and a short video, choose 10 to 100 founding seats at $10–$150 and set a backer goal. For a week, backers pledge with a card that's saved, not charged. If the goal is pledged, the campaign is funded, and backers are charged when you open access, within 90 days after it ends. Listing is free.
Questions
Is a fake door test the same as a smoke test?
Mostly, yes. Smoke test, fake door test and painted door test all mean showing an offer before the product exists and measuring who responds.
Is fake door testing ethical?
It can be, if you tell people right away that the product isn't ready and you don't take payment details. Leaving people to think they bought something is where it stops being honest.
What's a good click rate for a fake door test?
There's no universal number. Compare versions against each other, such as the same page at two prices, then confirm the winner with a pre-sale.