GTM Sauce

Product, onboarding and testing

Idea validation tactics

How founders tested demand before and while building: landing pages, fake doors, waitlists and early posts. 101 tactics from 67 founder interviews.

Most founders tested demand by putting the idea in front of people before or while building: a video or mock-up of the concept, a waitlist or small payment, or a rough version shipped within weeks. The strongest signals were people paying or committing early, and several of these apps went on to fast revenue. Weaker checks included calls with no network to draw on and betas that missed serious bugs.

Summary written 2026-09-26 from the tactics below. Figures are as founders stated them.

What worked, with the best evidence

An AI Bible study app · B2C · Bickster app

$29.99 beat $49.99 on day-one revenue; a later $39.99 now beats $29.99

'Proof of pay': ship a real app with a simple onboarding and a hard paywall showing one offer, submit every price you want to test up front, and run Apple Search Ads at the same daily spend (~$1K/day to learn fast; far less works over a longer period). Change only the lifetime price, walking it up: $4.99, $9.99, $29.99, $49.99. Read results directionally (day-one revenue per user), not for statistical significance. If you can't get past ~$4.99, drop or change the concept.

Workedvalidationpricing
App Masters · 2026-09-12

Once · B2C · disposable camera app for events

Got 12 events booked in one month, built the app, and hit $20K/month 83 days after launch

Define a 'commitment metric' for yourself and for users. For yourself: a specific date and a number (customers, clients, etc.) you must hit by then, so validation has a fixed time box. For users: the signal doesn't need to be payment, but must represent real usage; for Once it was event hosts agreeing to use the product at an actual dated event in front of friends and family, treated as nearly a proxy for payment. Their bar: 10 events with a real date and commitment before writing a single line of code.

Workedvalidation
Starter Story · 2026-05-10

Runify · B2C · ranked running app

2,000 waitlist emails and 90+ paid $5 in about 2 weeks

Used ChatGPT to make a one-page HTML site (runify.xyz) with a one-sentence pitch and rank images. Two options: pay $5 via a Stripe link to become an 'early adopter' (lifetime subscription once live) or join the email waitlist. All Reels traffic pointed there.

Workedvalidationlanding-page
The Superwall Podcast · 2026-03-17

Duolingo · B2C · language learning app

Uptake far above expectations; led to the subscription

After reading reviews where users asked to pay to remove ads, tested a one-time purchase of 30 ad-free days at $3, $5 and $10 instead of a subscription.

Workedvalidationpricing
Sub Club by RevenueCat · 2026-01-21

A poster store on TikTok Shop · B2C · guest's own store

3 sales on day one; the store went on to $100K in its first month

Took an unused poster design made for a client, put it on a poster mockup (posters were easy to source fast, which matters with TikTok Shop's two-day delivery), listed it on TikTok Shop and made one video with AI (ElevenLabs voice + Midjourney images). When it got 3 sales, he left a $100 deposit with a local print shop so they would print on each call and bill his card afterwards.

Workedvalidationorganic-short-video
The Superwall Podcast · 2025-11-11

BoldVoice · B2C · accent coaching app

Led to a ~$500K term sheet and YC; the coach still works with them

Before any code: cold-reached Hollywood speech/accent coaches (who work with actors) for differentiation. First coach, Ron, recorded lesson videos; ~12 beta users were manually sent the videos by email, emailed back speech recordings, and the coach gave asynchronous feedback. Used the pilot to pitch investors.

Workedvalidationpartnerships
Sub Club by RevenueCat · 2026-09-16

Visible · B2C · wearable for pacing chronic illness

5,000 waitlist signups in about a week

Over one weekend, put up a website with a 3D wearable mock-up bought on Fiverr and a one-line promise ('Pacing, made simple'), honest that the product didn't exist yet. The CTA went to a Typeform asking 'If we built this product, would you be interested in coming along for the journey with us?'

Workedvalidationlanding-page
Sub Club by RevenueCat · 2026-08-19

Visible · B2C · wearable for pacing chronic illness

Free app grew to ~50K users by word of mouth before any wearable

Instead of building the wearable first, built a free app. Took 100 people from the waitlist ('Founding 100'), ran a Facebook group with them and got on calls constantly. Learned users juggled 3-4 apps (symptom tracking, community, research) and combined them into one experience.

Workedvalidationfeature-development
Sub Club by RevenueCat · 2026-08-19

A niche subscription app · B2C · App Masters client

#1 in week one, 100 downloads a day, $1,600 first month, ~$20K MRR years later

Found a keyword (two variants, one word and two words, each ~30 search volume) that no competitor used in its title, based on an owned app ranking #1 for similar-volume keywords at 100-150 downloads/day. Asked a client with a new app idea to name the app exactly that keyword. Launched with no free trial.

Workedasopositioning-niche
The Superwall Podcast · 2026-07-22

Go Tall · B2C · height prediction app for teens

First viral format; 10-20 DMs a day asking for predictions

Noticed that under height videos on TikTok, people post their age, height and parents' heights, wanting a prediction. Made reply-to-comment videos predicting those commenters' heights. Inbound DMs requesting predictions served as proof that people care.

Workedorganic-short-videovalidation
Starter Story · 2026-07-19

Flame · B2C · daily question app for couples

Credited with saving the company; MRR went from $3K to $10K in under 8 months

VSC framework, run on TikTok before deciding what to build or scale. V (viral): the format or pain point has hit 100K+ views on several similar posts from accounts under 5,000 followers, so the content, not the account's reach, drove views. S (scalable): you can make 100 of them without burning out, using AI video/slideshows or cheap UGC. C (convertible): read the comments on posts that promote a product; if people ask 'what's the app? where can I find this?' it converts; 'lol', disagreement or controversy means it probably won't. After posting, keep scanning comments: a viral post with no product mentions is a sign of low conversion.

Workedvalidationorganic-short-video
Starter Story · 2026-06-21

ToneAdapt · B2C · guitar tone matching app

iOS app made ~$14K with 397 subscribers in its first month

Built V1 as a web app in about a week with AI coding (Supabase, Vercel, Mailgun, Stripe, OpenAI API, Tavily search API, Claude Code), charged from the start with Stripe, and skipped polish like logos. Web revenue and feedback came first; a few months later he built a native Swift iOS app (Vercel backend, Supabase, RevenueCat, Superwall paywall A/B tests).

Workedvalidationpayments-checkout
Starter Story · 2026-06-14

What didn't work, or only partly

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New tactics every Monday

The week's founder interviews, boiled down to what they did and what happened.

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