I saw the same and just assumed the author meant monthly growth targets to reach 20% growth per year. Did they really mean 20% month over month? That's insane.
Yes, the target growth rate taught by Y Combinator is 5-7% per week or 20-30% per month (at such high rates it's better to track weekly because otherwise you could fall too far behind before realizing it). http://www.paulgraham.com/growth.html
Wow, well... maybe it's just my ignorance, these people do this for a living. Just seems like a crazy number to me. I'm sure there's a lot of detail and reasoning behind that number.
Running a successful startup is crazy and unnatural; that's why it's so rare and that's also why there's backlash against that becoming the default mode of thinking.
Based on a quick calculation, to get from zero to one (billion) users takes just under six years at 7%/week growth.
It basically means doubling at least every five months, each five months, right?
So, each year, doubling your previous year, more than twice. But comparing the fractions to values pegged onto the first of each and every month, it’s expecting more than octuple values in less than 15 months, by January first of that calendar year.
To put those goals into explicit, concrete terms of absolute units:
Zero Month, January 1: First 100 subscriber accounts.
February 1: 120 paying subscriber accounts.
March 1: 144 paying subscriber accounts.
April 1: 173 paying subscriber accounts.
May 1: 208 paying subscriber accounts.
June 1: 250 paying subscriber accounts.
July 1: 300 paying subscriber accounts.
August 1: 360 paying subscriber accounts.
September 1: 432 paying subscriber accounts.
October 1: 518 paying subscriber accounts.
November 1: 622 paying subscriber accounts.
December 1: 746 paying paying subscriber accounts.
January 1: 895 paying subscriber accounts.
... taken to month 15:
13: 1,074 customers
14: 1,289 customers
15: 1,547 customers
But there’s a cold calculus to this way of thinking: Why should a multi-millionaire take money out of proven investments with 10% or 15% returns, since they’ll double in ten years or less?