The client was struggling to build a case to defend their marketing spend in the context of a belief within the business that pricing was the major contributor to sales and retentions. This "gut led" view was how business was always done. We were tasked with performing a full Econometric Attribution, looking at all potential drivers of sales including marketing, pricing, macroeconomic drivers, customer journies and behaviour. The particular challenge with this project was to keep both the marketing and pricing teams engaged in the process, and to produce a story that provided absolute clarity on the drivers of sales, losses and product transfers, and what part each of these drivers played in the process of acquiring or losing customers. As expected, both marketing and pricing had their own roles to play, but for the first time they could see the size of the effects of all drivers of sales (and losses). This allowed the marketing team to back up decisions on their £7m marketing budget with science in a way that allowed the pricing team, and rest of the business, to understand the wider effects.