I’m Amit Roy, a commercial strategist. For nearly a decade I’ve helped brands work out where their marketing money should go and what it actually returns — starting at American Express, then at global media agencies, with brands across many categories.
Starting on the commercial side of a business shaped how I think about marketing. Every dollar had to show what it brought back, and “that’s what the industry does” was never an answer. That habit stayed with me: before accepting a rule, ask what would have to be true for it to work — and what would prove it wrong.
Much of marketing runs on rules of thumb. Reach as many people as possible. Split the budget 60/40. Cut what you can’t attribute. Some of these hold some of the time. But they’re usually handed on as conclusions, without the reasoning that tells you when they apply — so they get used in situations they were never meant for.
Meanwhile, finance is right to ask what marketing money actually does. Too often the answer is a chart of attributed sales, which credits the last thing a buyer saw and misses most of what made them buy.
It goes back to first principles. Instead of starting from a rule, each module starts from how buying actually works, and lays out the logic and arithmetic underneath. Those parts hold whatever the numbers are — they aren’t a matter of opinion.
Where a conclusion depends on an assumption, the module says so plainly, and keeps it separate from what has to be true. The numbers are illustrative, not fitted to any real brand. The aim isn’t to tell you what your brand should do. It’s to make the reasoning visible, so you can test it against your own.
We’re all buyers. You’ve bought the other brand because yours wasn’t on the shelf, gone out of your way for one you really wanted, and kept buying one without thinking twice. So most of what these modules show will feel familiar. Use that as a way in — then let the logic, not your own habits, be the test.
Marketers early in their career who want to understand how marketing works, not just its vocabulary. Experienced marketers who want to check the rules they were taught. And the finance partners they work with, who need a shared, plain way to talk about what marketing investment does.
Questions, disagreements, or a mechanism you’d like to see modelled — I’d like to hear them.