Stacy's Brain

"Stacy's Brain is a database of marketing and growth statistics, built as marketing's collective memory. It helps marketers, founders and solo builders find numbers they can actually build a strategy on: 750+ insights from 80+ studies, experiments and vendor reports. Every insight shows its source, sample and a reliability tier from S to D. The tier is based on methodology, sample size, age of the evidence and vendor interest, so you can see how much to trust a finding before you use it. On top of the database: research reviews, answer collections for common marketing questions, paid media benchmarks and a weekly newsletter."