C&A was set up in Sneek in 1841 by the brothers Clemens & August Brenninkmeijer, but the real breakthrough that led to almost a century of success took place in Amsterdam 65 years later… In 1906 Clemens’s son, Bernard Joseph, discovered a surefire way to make net profits snowball. The underlying Opportunity Cost and Contribution dollars system was kept so secret, that it was eventually forgotten. Today C&A has largely returned to the less profitable pre-1906 system of planning, pricing and evaluating its assortment. This booklet reintroduces the surprisingly simple math behind Joseph Brenninkmeijer’s retail method. Successful retail founders around the world such as Mrs. B (NFM), Ingvar Kamprad (IKEA), Joe Coulombe (Trader Joe’s), Karel van Eerd (Jumbo) and Jeff Bezos (Amazon) have discussed and written about the drawbacks of conventional gross margin percentage frameworks when managing their assortments, pricing and markdowns, but didn’t know the German Opportunity Cost (manufacturing) model could be used as an alternative. This might be the first explanation of how the alternative money counting framework works in practice, was developed over generations at C&A, and how it could be implemented again in your company today.