Since first learning about customer development a few years back we’ve applied it to many different ideas. Along the way we’ve found we were consistently making the same mistakes over and over again. And I’d see other founders falling for the same traps. I’ll list them out here so hopefully you can avoid them but let me warn you, it’s very easy to fall into these traps, and I still find myself battling my way out of them.

1) You’re assuming you know your customers.

Okay, this seems like an obvious one but I have to hammer it home. Whether you’re “scratching your own itch” or going into a brand new market, you have to enter it assuming you have no idea how your customers behave. You’ll be amazed at how many of your own assumptions are wrong.

Here’s one example: on our signup form we used to ask for the “Subdomain”. Basically, each user’s account exists under it’s unique subdomain, so we’d ask which subdomain they’d like. We added that field in without much thought but the amount of confusion it caused was surprising. We’d get emails asking what’s a subdomain. Many would put in their company’s full website and would be totally confused when they’d receive a validation error. It caused way more headache than necessary. We had assumed that 1) our customers would easily grasp the subdomain concept and 2) they’d value their subdomain enough that they’d want to choose it. Both those assumptions were wrong.

The solution was super easy: we were already asking for their company name, we just automatically converted that to their subdomain. We haven’t had any issues since.

Biggest takeaway for me was that if we can’t even predict how our customers will fill out a simple form, there’s lots of other assumptions that could be wrong. So I make sure to always double check.

2) Your customers are assuming they know other customers.

So you’re talking to your customer’s to double-check your assumptions. Excellent. You ask “what features do you think others would want?” and you get a huge list of features. Great, time to go build.

Hold on a sec. Just the same as principle #1, asking your customers to guess what others would want can lead you astray. They’re basing it off their own assumptions. Unless they say “I personally want this feature”, then you have to almost discard what they say.

This applies to finding out what to charge. Never ask “what do you think someone would pay for this?”. Always go for the “what would YOU pay for this?”. That’s 100 times more effective. And it won’t clutter your product with assumed features.

3) Your customers assume they know themselves.

Your customers can’t reliably predict what they would want in the future. It’s better to ask what they actually are doing.

Here’s an example. When we were developing a photo-editing application, we’d have some customers request a way to export to dozens of different file formats. The followup question we’d then ask them is: which file formats do you currently export use? And the actual list was just a half dozen.

If we had unlimited time with unlimited resources we’d definitely implement all the requested formats. But since we’re a small startup, it’s better for us to perfectly nail down the required features first, and then later move on to the nice-to-haves.

So make sure you’re focusing on what they currently need (“hair on fire” feature) and not on what they might like.

4) You’re creating imaginary assumptions.

This is a huge mistake I see everyone make. If there’s one thing I want you to learn from this post, it would be this. Don’t seed your customers with assumptions. For example, this is the wrong way to gauge interest for your idea:
“Would you want feature X in this application?”

Why is that a bad way to ask? Because it’s too easy to say “yes”. Who would reject something that’s given to them. It’s like saying “would you want free ice cream?”. Almost everyone would say “sure, I’ll take it”.

But this way you won’t learn what people truly need. A better way to ask is:
“Which feature would you want in this application?” Or better yet: “What type of application would you want?”

When you ask an open-ended question like that, you’ll get a much better grasp of the problems they’re really facing. And guess what? If you can then solve those problems, you’ll have a hit on your hands.

So what?

I’ve made many mistakes while applying the customer development principles. And even to this day I still find myself making these same mistakes. But it’s like a muscle, the more you exercise it, the stronger it gets. And the better you get at not making incorrect assumptions. Hopefully this helps you on your journey to amazing products.