Got a startup idea? Great. Now all you need to do is to figure out if it's worth investing untold hours and years of stress to make it a reality.

There's no shortage of ways to do that. You could turn to Kickstarter or another crowdfunding platform to see if customers are really as keen on your product as you are before you actually put it into production. You could build a minimum viable product (MVP) and send it out into the world to collect feedback, as many startup gurus recommend. But maybe there is a simpler initial test you should do to see if your idea merits even this level of effort.

Find Yourself a Napkin and a Pen

The suggestion comes from Justin Jackson, a product manager for a "profitable" but unnamed startup who blogs about his entrepreneurial side projects and lessons from his day job. He builds his idea upon the commonly accepted startup wisdom that a genuine passion for and connection to the space you propose to enter is generally a prerequisite for success. Or, put simply, if you’re going to build a database business, you need to really love databases. If you’re going to sell organic cosmetics, you need to know a lot about them.

Sounds straightforward, but how can you know if both your grasp of the niche and your depth of both knowledge and connections is sufficient to really have a chance of success? Jackson suggests you find yourself a pen and paper (the proverbial back of a napkin will do!) and try this exercise.

"Write out the names of five people who need your product. Just five people," he suggests. Sounds simple, but Jackson explains, "this is an effective test because it makes it real. If you built this thing, who would buy it? Can’t think of five people? That’s a red flag. Are you targeting a product at a group of people you don’t yet have a connection with?"

How Do You Measure Community Ties?

This little activity isn’t a marketing exercise to help you figure out whom you should target first as customers. It’s about testing your own level of connection--or lack thereof--to a real community and its real problems.

"At the beginning, when you’re deciding what to build, knowing a few potential customers by name proves something. It shows that you’re involved in their community; that you’ve been listening to their problems. When you can name your first customers, the people you know need a solution, you can build your product with confidence," he writes.

If you can’t name a handful of living, breathing people (even if you only know them online, not in the flesh) that want this thing, it’s unlikely you understand the market well enough. Those who can’t cross this first hurdle may want to invest more time in research and relationship building before they actually start building their businesses.

Does your startup idea pass this test?