Notes from the operator behind Cal AI.

Weekly insights and lessons on AI, business, and life from Jake Castillo.

Newsletter Archive

Jun 23, 2026

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2 min read

The ultimate cheat sheet: influencer marketing edition

read this or blow your budget

Jake Castillo

Jun 20, 2026

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3 min read

7 underrated app k*llers you need to know

bookmark this

Jake Castillo

Jun 16, 2026

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1 min read

The 3-to-5 rule that saved us millions

how we knew when to kill a campaign

Jake Castillo

Jun 13, 2026

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1 min read

Why we let Cal AI bleed $$$

profit was never the point (at first)

Jake Castillo

Jun 2, 2026

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1 min read

Why we paid every influencer 100% upfront

it almost broke us, but it was the right move

Jake Castillo

May 27, 2026

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1 min read

The 20-second influencer test that saved us millions

stop building a case for bad creators

Jake Castillo

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