Take a minute to poke around both of these sites [Medium and Genius]. See how different they are? How they’re designed, the audiences they seek to reach, the way they work with the larger web? All those millions of things that make them different? As similar as their data and technical architecture might be in an abstract, conceptual way, the experience of each is radically different. Those differences are the result of product management. So that’s one way to define “product,” as the observable difference between Genius and Medium.

Paul Ford being smart again, in It’s Kind of Cheesy Being Green.