Metaphor: a startup is a seed in a cracked sidewalk

A marginal but growing market

ignored by incumbents

is like a crack in the sidewalk,

and a startup is like a seed.

 

The crack gives the seed a place to germinate.

 

At first it's just a little shoot,

but if it keeps growing

it will eventually

push the sidewalk apart

Metaphor: government regulation is like herbicide

Corollary:

If you see a stretch of sidewalk full of cracks

with no shoots growing out of them,

it has probably been sprayed with some sort of herbicide,

like the RIAA or government regulation.

(src: Tweet: a startup is a seed in a cracked sidewalk - Paul Graham)