It’s scary to bet it all on one idea. “Don’t put all your eggs in one basket,” they say. Of course, there’s a corollary: “If you chase two rabbits, you won’t catch either.”

You may feel an ever-present temptation to explore different ideas or carry multiple side projects. And I say “carry” deliberately; like going on a hike, every extra ounce burdens you and makes the journey that much more difficult. Regardless of the reasons behind side projects, it’s unrealistic to believe that a small team, let alone one person, can effectively carry side projects. Don’t get me wrong–you need to explore ideas to find the right one for you. But there comes a time where you must commit and focus, and that time is usually sooner rather than later. So how do you know?

Side projects are convenient ways to avoid commitment–if something fails, it’s no great loss since you were never emotionally invested in the first place. You don’t have anything really pushing you. Moreover, side projects rarely make it past the 80% phase: the first 80% of the work is the easy part, but following through on the last 20% determines whether something actually ships.

I didn’t realize it at the time, but my original plan to open-source what would eventually become Sifter was a cop-out. I was scared of responsibility. Paying customers? Processing credit cards? I didn’t want any of that–I just wanted to build something. Open source is a great model for libraries, components, and frameworks, but it’s not as inherently self-sustaining as a business. Thank goodness friends helped me see this before I missed the boat. Looking back on Sifter today, I know I would have been distracted with other side projects if Sifter hadn’t also been my livelihood.

A real project is something you deeply believe in. It doesn’t have to change the world, but you have to believe it’s meaningful to some group of people. Chances are, if you’re pursuing too many side projects, it’s because you don’t believe in one of them enough. You need focus and a vision to help guide your decision-making. If you feel like you’re spread too thin, you’ll have to make some hard decisions. Choose that one thing you can’t stop thinking about, and go after it.

My goal was always to make the software development process more accessible to people who aren’t as technically inclined. With that goal in mind, it’s easy for me to determine whether a side project supports or detracts from that vision. This book was the first side project our team felt was relevant and worthy, and we pursued it because it’s closely aligned with our long-term vision to help more people create software.

The biggest roadblock for most people is finding out how to validate if an idea is the idea. If I had a dollar for every time someone asked how to validate their idea and know whether they’re focusing on the right thing, I’d have quite a bit of extra spending money. One of the scariest things is trying to figure out whether you’re doing the right thing. And there’s no easy answer.

The only way to know whether your idea is valid is to ask people to pay for it: if you’re not asking people to pull out their credit cards, nothing else matters. People may tell you they’d pay for it–and they might even tell you how much they’d pay for it–but talk is cheap.

The immediate follow-up question is almost always about how to ask people to pay for something before you’ve built it or before it’s ready. After all, you wouldn’t want to waste your time building something nobody would pay for. The answer is as straightforward as it is disappointing: you can’t. You have to build something on the conviction that people will pay for it; and to avoid wasting your time, you need to build the simplest possible solution you think people will pay for.

The beauty of this is that you’ll have incredible motivation to actually ship. we’ll talk more about this later, but you always need to focus on shipping. And you’ll have to ship to find out whether it’ll work–there’s no reward without risk.