Growth with Sean Ellis

Growth with Sean Ellis

In Early-Scale Growth, the Dominant Cost Is Not CAC. It’s Time.

How speed of learning shapes sustainable growth engines

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Sean Ellis
Jan 28, 2026
∙ Paid

One of the most common mistakes I see startups make is optimizing for efficiency too early.

They fixate on CAC ceilings, bid caps, and channel ROI before they have enough evidence that their growth model can actually scale. On paper, this looks disciplined. In practice, it often slows learning so much that the company burns far more money than it saves.

H…

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