Networks effects can lead to massive, rapid growth. Amazon has leveraged this little sketch by Jeff Bezos in 2001 for mega growth — Amazon calls it a virtuous cycle — and, more recently, the Uber variation, by David Sacks explains much of Uber’s wild ride.

When you build a platform that leverages network effects right it can enable growth way beyond what has historically been possible. Also, see Metcalfe’s Law.

The ‘Virtuous Cycles’ of Amazon and Uber

A full moon that hits twice in a calendar month. Given the cycle from full moon to full moon is about 29.5 days it doesn’t happen very often that this coincides so nicely. And February never has a blue moon.

I like this definition, but it is apparently a modification to the original definition which is a little more complicated. Given the 29.5 day cycle, most seasons of 3 months have 3 full moons. But every now and then, a season would come by, like Sep, Oct, Nov in the sketch, where there would be 4 full moons. The 3rd of these was known as a blue moon, or a seasonal blue moon. See why I like the modern definition?

Here’s a good article that explains the subtleties and history of blue moons.

Check out more moon or astronomy sketchplanations

What is a blue moon?

This is military strategist John Boyd’s framework for combat operations that also turns out to apply quite well to businesses and learning in general. It’s really not that far from the ol’ test-learn cycle or a good design process.

There’s lots of nuance to his framework, but some of the application of it that I like includes:

The faster you can do this loop — at your startup or in a fight — the more stuff you will get to try and the faster you will learn

If you’re in competition with another entity then completing your OODA loop fast, and acting to change the environment for them, disrupts their loop and forces them back to observe before they can act. It slows them down and creates confusion

I learned about it from Reid Hoffman’s excellent Masters of Scale podcast.

OODA Loop