Smoke Test Landing Page: Measure Demand Before Building
Short answer
A smoke test landing page presents a product that does not exist yet, with a price and one call to action, and counts how many strangers take a step that costs them something, such as pre-ordering. It only tells you something with a few hundred visitors and a pass mark you set before launch.
Buffer, the social media scheduling tool, started as a two-page test. One page explained the product, the next asked for an email address because it was not ready yet. Founder Joel Gascoigne then slipped a pricing page in between, so visitors had to pick a plan before signing up. He has written publicly that the clicks and sign-ups were enough signal to start building the real thing.
That is the whole idea of a smoke test landing page. You make an offer, you watch what strangers do with it, and you decide before writing code. The hard part is not building the page. It is reading the result honestly.
What the test answers, and what it cannot
Interviews tell you a problem exists. This test asks a different question: will people who have never heard of you take a step that costs them something, when shown a concrete offer with a price?
It does not tell you whether the finished product will retain anyone, whether customers will recommend it, or whether the price is optimal. Treat it as a filter. It removes ideas that already fail at the offer stage, which is cheap to discover now and very expensive to discover after six months of development.
Run it after your problem interviews, not instead of them. Our guide on how to validate a business idea shows where it fits in the sequence.
Anatomy of a smoke test page
Keep it short. One screen on a laptop is plenty.
- A headline that names the problem in your customers’ words. Steal phrases straight from your interview notes.
- Two or three sentences on what the product does and who it is for.
- A price, stated plainly. No price means you are measuring curiosity.
- A single button with a concrete action: “Pre-order”, “Reserve a seat”, “Request a pilot”.
- An honest post-click page: it is being built, here is the expected launch window, do you want to hear when it is ready?
The value of the signal depends on what it costs the visitor. An email address is the weakest. Two or three required questions about team size or current tools cost time and give you segmentation for free. Deposits and card-on-file pre-orders are the strongest signal you can get without a product.
Now the rules. Collecting emails in the UK or EU means a privacy notice, and marketing emails later need consent under GDPR and, in the UK, PECR. If you take money from US customers, the FTC’s Mail, Internet, or Telephone Order Merchandise Rule expects you to ship within the time you state, or within 30 days if you state none, otherwise you must offer a refund or get consent to the delay. Promise a realistic date or none at all.
Getting traffic that means something
Paid ads give you a known cost per visitor and a defined audience, which also lets you estimate future acquisition cost. Their weakness is noise: tiny budgets spend the first days inside the platforms’ learning phase.
Traffic from communities, newsletters or direct messages is cheaper but warm. People who recognise your name click more. Keep the sources separate in your analytics and never blend them into one rate.
Consider running two versions with different prices. You will not find the perfect price this way, the numbers are too small. You will see whether interest collapses at double the price or barely moves, which is worth knowing early.
How many visitors is enough?
This is where most smoke tests fall apart. Eighty visitors, four sign-ups, five percent, champagne. Statistically, that result is nearly meaningless.
The quick approximation for a 95 percent interval around a measured rate p with n visitors is p plus or minus 1.96 times the square root of p(1 − p)/n. With small samples it is rough, but it is fine for planning.
Own calculation using the normal approximation, 95% interval. With 100 visitors, the true rate could be anywhere from about 0.7% to 9.3%.
Aim for 300 to 500 visitors per variant for a first decision. Below that, only very clear results are readable: almost nobody, or a surprising crowd.
Setting the pass mark from your own economics
Forget borrowed benchmarks. The number that matters comes from your price and what you can afford to spend acquiring a customer.
- First-year revenue per customer
- $600
- Affordable acquisition cost (one third)
- $200
- Assumed cost per paid visitor
- $2
- Assumed share of leads who later buy
- 20%
- Affordable cost per lead: $200 × 20%
- $40
- Required page conversion: $2 ÷ $40
- at least 5%
Every figure here is an assumption for a fictional B2B tool, not market data. Replace them with your own.
If 500 visitors leave you clearly below that line, this channel at this price probably does not work. The idea is not necessarily dead. Direct sales, a higher price or a narrower audience might change the maths. Either way, you know now rather than after building.
When the rate clears the bar, check whether the pool of potential buyers is big enough with our walkthrough on calculating TAM, SAM and SOM.
Three outcomes and what each means
Clearly above your pass mark: enjoy it briefly, then check that the sign-ups came from the audience you intended and that their answers to the extra questions make sense. If they do, start building the smallest product that delivers the core result.
Just above or just below: the most common and most annoying result. Rather than extending the test forever, change one variable decisively, such as audience, price or headline promise, and run it again with the same visitor count.
Almost nobody converts: painful. Before burying the idea, check that the traffic was right. A badly targeted ad that reached students instead of procurement managers can make any idea look bad. If the audience was right, you just learned something important for very little money.
Mistakes that ruin the result
No price on the page, so you measure how interesting the topic sounds.
Several competing buttons. “Learn more”, “Join newsletter” and “Book a demo” on one page produce clicks you cannot compare.
Stopping early because the first day looks great. Early numbers swing wildly. Fix the visitor count in advance and wait for it.
Ignoring the people who converted. Everyone who pre-ordered or filled in the extra questions deserves a call. Phone the first ten. Those conversations often teach more than the percentage, and those people make ideal first testers once you start building, as described in our breakdown of MVP development cost.
You do not need an agency for the page itself. Any site builder will do. If the test passes and you want an engineering partner to get to a real product, studios such as OnlineBuilders take on selected builds.
Next step: work out your own pass mark with real numbers, write it down somewhere public to your co-founder, and build a page with exactly one button.
Questions people ask
What is the difference between a smoke test and a fake door test?
A smoke test usually validates a whole product concept on its own landing page. A fake door test adds a button for a feature that does not exist yet inside a live product. Founders without a product almost always want the smoke test.
Is it ethical to sell something that does not exist?
Yes, if you are honest straight after the click and never keep money without saying what will be delivered and when. If you take payment, offer a clear refund and stick to it.
How much should I spend on ads for a smoke test?
Enough to reach a few hundred visitors per variant. Depending on your niche and cost per click, that is often a few hundred dollars or pounds. Community traffic is cheaper but not comparable to paid traffic.
What conversion rate counts as a pass?
There is no universal number. Work the threshold out from your price and acquisition budget, and weigh it by how costly the action was. Two percent pre-orders beat twenty percent email sign-ups.
