What documentation should I maintain for campaigns?

As an e-commerce store owner running multiple campaigns, I've learned the hard way that documentation isn't just bureaucratic paperwork—it's a critical business survival tool. Last quarter, I ran several promotional campaigns across different channels, and without proper tracking, I was flying blind. I couldn't definitively tell which campaign drove the most revenue, which discount strategy worked best, or how different audience segments responded. My team was constantly asking, 'What was our exact discount strategy for Black Friday?' or 'How did we segment customers for that summer sale?' The lack of systematic documentation meant we were recreating the wheel each time and losing valuable institutional knowledge. Worse, during our end-of-year review, I realized we had no clear audit trail to understand our marketing performance. Growth metrics became guesswork, and strategic planning felt like throwing darts in the dark. I needed a systematic approach to document not just the campaign parameters, but the rationale, performance metrics, audience targeting, and lessons learned. This isn't just about record-keeping; it's about building a strategic knowledge base that helps us continuously refine our marketing approach and make data-driven decisions. The right documentation can transform scattered campaign efforts into a cohesive, learning-oriented marketing strategy.