“Shielding yourself from the inevitable question of whether somebody will pay you is very harmful to a founder... you can make a lot of metrics go up before you get to that one not being able to.”

Validate Willingness to Pay Early — Don't Kick That Can Down the Road

Phil distinguishes two types of startups: those with clear precedent that users will eventually pay (where building to scale first makes sense) and those inventing something genuinely new (where deferring monetization is existential risk). For the second type, every growth metric is a vanity metric until you know someone will actually pay. He advises founders to tackle willingness-to-pay early, because discovering it won't work at year three is far more damaging than finding out in month three.