CAC (Customer Acquisition Cost)

The total sales and marketing spend to acquire one paying customer.

Example

$4,000 on ads and sales in a month producing 20 customers is a CAC of $200.

Founders routinely exclude their own salary and time from CAC, which makes early numbers look far better than reality.

LTV (Lifetime Value) — The total gross profit you expect from one customer over the whole relationship.
Payback period — How long a customer takes to repay what you spent acquiring them.
Unit economics — The profit or loss on a single customer, once you strip out fixed costs.

Getting your first ten customers — Not from a channel. From you, personally, one at a time — and that is the correct way to do it. (12 min)
Choosing a distribution channel — Most startups win with one channel, not five. Picking it is more important than executing it well. (12 min)
Entering another country — Usually later than founders think, and usually harder. What has to be true before it is worth the distraction. (12 min)
When scaling actually starts — Scaling is not growing. It starts only once the thing you do works repeatably — and starting early is how good companies break themselves. (12 min)
Scaling sales and marketing — You cannot hire your way to revenue. You can only hire people to run a motion that already works — so the motion has to exist first. (14 min)
CAC, LTV and payback — Whether each customer makes you money — and whether growing makes things better or just makes the hole bigger, faster. (15 min)