The method blog
One method at a time: how it works in plain words, the formula unpacked, where it lies to you, and a notebook and spreadsheet you can run on your own data. Each essay names its sources and shows its working. It is not marketing collateral — it is the maths, written to be checked.
Marketing mix modelling · 15 min read · Interactive · Video
How much should I spend on each channel — and where does the next euro stop paying off?
A per-channel cost-per-sale tells you where sales happen, not where the next euro works hardest. Marketing mix modelling learns a diminishing-returns curve for every channel and reads the return on the next euro — with a range on every number. The capstone of the series: an 8-minute video shows why attribution, a geo-holdout, and MMM together triangulate a budget move that eyeballing one number gets backwards.
Experiments · 13 min read · Interactive
Is this channel actually driving sales — or would those sales have happened anyway?
Attribution tells you which channels show up near your sales; it cannot tell you which caused them. A geo-holdout turns a channel off in some regions and reads the difference — the closest a marketer gets to proof — with a notebook and a spreadsheet to run it yourself.
Attribution · 14 min read · Interactive
Which marketing channels actually drive sales — not just show up at the close?
Last-click hands every sale to the final touch and starves the channels that start journeys. Markov "removal effect" attribution scores each channel by how much conversions drop when it is taken out — with a notebook and a spreadsheet to run it yourself.