Most lead scoring projects die in week three. The 30-minute version that actually ships: 5 dimensions, a one-paragraph rubric, and one =AI() formula in Google Sheets powered by Gemini. Sales filters by green, you re-score weekly.
A one-page Google Sheets dashboard with 8 marketing KPIs and a Gemini =AI() cell that writes the week-over-week narrative for each metric. Built in 90 minutes, fits in a Slack screenshot, kills the 20-minute Monday meeting.
You can build a real 4-channel MMM (Marketing Mix Model, 营销组合模型) in a Google Sheet in one afternoon — no Python, no data engineer, no $40K vendor. I walked a DTC client through it last quarter. The build took 3 hours, the adstock decay curves are written by ChatGPT, and the sensitivity test exposed a $14K/month waste nobody had spotted.
