Ask about last Friday, not about your idea.
Ten honest conversations tell you more than any survey. The exact words people use become your headline and your first post.
Chapter 1: Friday, 4 p.m.
Every Friday, the same three hours.
Your sister is a bookkeeper. Every Friday afternoon she stops doing the work she's paid for and starts chasing clients for receipts: emails, texts, a few awkward calls.
You can code a little, and you start to wonder whether other people would pay to make this go away.
3 hrslost every week, by one bookkeeper
Chapter 2: The first week
Ten calls. Eight of them describe the same Friday.
You don't pitch anything. You ask ten bookkeepers one question: "Walk me through the last time you collected receipts." Then you stay quiet.
Eight describe the same chase in almost the same words. Two say it's fine. You write down the exact phrases the eight used, because those will become your headline.
The lesson: ask about the last time it happened, not whether they'd use an app. People are kind about ideas and honest about Fridays.
Go deeper: Ten calls before ten lines of code
Chapter 3: Two weeks in
One page, one promise, forty names.
Before building anything, you put up a single page that says, in the bookkeepers' own words: "Stop chasing receipts on Friday." Below it, one box for an email address.
You share it in two bookkeeping groups with a short, honest post. In two weeks, forty people sign up to be told when it's ready. Three of them ask if they can pay early.
$0spent so far
Chapter 4: Month one
Built in the evenings, on free plans.
After work, you build the first version, with an AI assistant writing the first draft of the code. You read every line before anyone else touches it.
The product does one thing: every Thursday, each client gets a friendly reminder with a link to upload receipts from their phone. Everything runs on free plans. It costs nothing, which feels like a win.
A catch you learn early: some free databases pause after a week with no activity. You open the app every few days so it stays awake.
Go deeper: Free plans, mapped
Chapter 5: Month two, launch day
Launch day breaks a free plan before lunch.
You invite all forty people. Welcome emails, sign-in links and the first reminders to their clients go out at once, and pass the free email plan's limit of 100 a day. Some never arrive.
You upgrade email that afternoon, and move hosting to a paid plan too, before anyone has paid you. A paused app in front of paying customers would cost more than the plan.
$40a month in tools, $0 revenue
Go deeper: Free tiers that break on launch day
Chapter 6: Month three
Your first $20 arrives from a stranger.
A bookkeeper you've never met subscribes to the $20 plan. It's the best notification you have ever received.
The card processor keeps $0.88 of it, plus a small fee for running the subscription. You shrug: less than a dollar. You also move the database to a paid plan, so real customer data never sits on something that can pause.
$66a month in tools and fees, $20 revenue
Go deeper: What card fees really cost
Chapter 7: Month four
The first goodbye is a lesson in spam folders.
With 23 paying customers, you get your first cancellation. The reason stings: the bookkeeper's clients never saw the reminders. They were landing in spam.
The emails were going out from a shared, generic sender address. You set up sending from your own domain and add the authentication records that prove the emails are really from you. It takes one evening and costs nothing. The next week, reminders arrive.
1 of 23customers lost, for a reason that was fixable
Go deeper: Why your emails land in spam
Chapter 8: Month six
One hundred customers, and one surprise.
Word spreads through bookkeeping groups. By month six, a hundred bookkeepers pay $20 a month: $2,000 in revenue.
You finally sit down with your bill. Hosting, database and email barely moved. The card fees grew with every single customer, and now make up most of what you pay.
Your bill: $167 a month. $102 of it is card fees.
100paying customers, card fees $102 a month
Chapter 9: Month seven
The one cost you can actually change.
Card fees have a fixed part on every charge, so twelve small payments cost more than one big one. You add a yearly plan: $200 instead of $240, two months free.
A third of your customers switch. They save money, you get paid up front, and each of them costs you about four dollars less in fees every year.
$10.56 → $6.10card fees per customer, per year
Go deeper: Monthly vs yearly pricing