● The Playbook

The method, given away.

Every article here is written so you can run it without buying anything. No gated PDFs, no invented benchmarks — arithmetic you can check, and an honest note about where each method runs out.

Fundamentals

Break-even ROAS: the only number that says an ad is working

6 min read

“What ROAS do I actually need?”

Most advertisers judge ads against a ROAS target someone guessed. Here is how to derive yours from gross margin in one line, and why a 3.0 target can be either reckless or timid depending on what you sell.

Read it →

What COGS actually includes (and the four costs everyone forgets)

7 min read

“What does this order actually cost me?”

Every profit number you will ever calculate rests on one figure, and it is usually wrong. Here is how to build a defensible cost per order in an afternoon, and which costs quietly destroy margin at scale.

Read it →

Attribution

Why Meta and Google both claim the same sale

7 min read

“Why don’t my platform numbers add up to my real revenue?”

Add up the conversions your platforms report and you will find more sales than you made. Here is exactly where the double-counting comes from, and what to do about it without buying anything.

Read it →

Measurement

How to read a cohort without a data team

8 min read

“Are these customers worth anything after the first order?”

First-order ROAS judges a customer on the day you met them. Here is how to build a simple cohort view in a spreadsheet and find out what a channel's customers are actually worth by month six.

Read it →

Incrementality tests you can actually run as a small business

7 min read

“Would these sales have happened anyway?”

Most incrementality advice assumes an enterprise budget. Here are three designs that work at SMB scale, what each can and cannot prove, and how to avoid fooling yourself.

Read it →

Creative testing that proves something

8 min read

“Is this creative actually better, or did I get lucky?”

Most creative tests are decided by noise. Here is how to size a test properly, what to change, why platform A/B tools flatter their own winners, and how to judge a creative on profit rather than clicks.

Read it →

Scaling

Scaling without killing it: why average ROAS can’t answer “spend more?”

7 min read

“Can I safely spend more on this?”

Average ROAS describes money you already spent. The decision in front of you is about the next krone. Here is how to measure marginal return and find the point where scaling stops paying.

Read it →

Operating

Your first 30 days of profit tracking

9 min read

“Where do I even start?”

A week-by-week plan to move from platform-reported ROAS to a profit number you trust — using tools you already have. Including a warning about what the numbers will do to your mood in week two.

Read it →

Every method here runs out at the same place.

You can derive your break-even, read a cohort and size your attribution gap in a spreadsheet. What you cannot do by hand is keep it current, match every order to the ad that caused it, and have the answer waiting on a Monday morning. That is the whole job of Kepra.

See it on demo data →