The minimum critical mass

For your idea to spread, your app to go viral, your restaurant to be the place, it's likely you'll need to hit critical mass.

This is a term from physics, describing the amount of plutonium you need in a certain amount of space before a nuclear reaction becomes self-sustaining.

Once enough people start driving your new brand of motorcycle around town, it's seen by enough people that it becomes accepted, and sales take off from there.

Once enough people who know enough people start talking about your new app, the touchpoints multiply and organic growth kicks in.

Once enough readers read and engage with your book, it's no longer up to the bookstore to push it… people talking to people are the engine for your growth.

It's sort of the opposite of Yogi Berra saying, "No one goes there, it's too crowded." When you hit the right number of conversations, the buzz creates its own buzz, popularity and usage creates more popularity and usage.

The thing is, though, most marketers are fooling themselves. They imagine that the audience size necessary for critical mass is right around the corner, but it's actually closer to infinity. That, like a boat with a leak, you always have to keep bailing to keep it afloat. If you don't design for a low critical mass, you're unlikely to get one.

This is why most apps don't ever take off. Not because they weren't launched with enough fanfare, not because the developers didn't buy enough promotion or installs—because the r0 of virality is less than one. Because every time you add 10 users, you don't get a cycle that goes up in scale, you get one that gradually decays instead.

The hard work of marketing, then, isn't promoting that thing you made. It's in building something where the Minimum Critical Mass is a low enough number that you can actually reach it.

Facebook, one of the finest examples available, only needed 100 users in one Harvard social circle for it to gain enough traction to take the campus, and then jump to the Ivy League, and then, eventually, to you.

My book Purple Cow was seeded to about 5,000 readers. That was all the direct promotion it needed to eventually make its way to millions of readers around the world.

How many people needed to start carrying a Moleskine or selfie stick or a pair of Grados before you decided you needed one too?

Yes, of course, sometimes the route to popular is random, or accidental. And betting on lucky is fine, as long as you know that's what you're doing. But the best marketers do three things to increase their chances:

  1. They engineer the product itself to be worth talking about. They create a virtuous cycle where the product works better for existing users when their friends are also using it, or a cultural imperative where users feel better when they recommend it.
  2. They choose their seed market carefully. They focus on groups that are not only easy to reach, but important to reach. This might be a tightly-knit group (like Harvard) or a group that shares a similar demographic (like the early readers of Fast Company) or a group that's itching to take action…
  3. They're hyper-aware of the MCM and know whether or not they have the time and the budget to reach it.

Making your MCM a manageable number is the secret to creating a hit.