We Let Gemini Write 100 Proposals. Here's What We Learned.

We ran an experiment: write 100 real proposals using AI, then compare win rates with proposals written manually by experienced agency owners.

The result surprised us

AI-generated proposals (with light human editing) had a 64% win rate vs 61% for fully human-written proposals. Not dramatically better — but not worse either, and dramatically faster.

What AI does well

Executive summaries. AI consistently writes clearer, more client-focused executive summaries than humans do. It avoids agency jargon and focuses on client outcomes. It also writes excellent project scope and deliverables sections.

What AI does badly

Pricing psychology. AI doesn't understand your specific market positioning or your client relationship. Always write the pricing section yourself. Also: testimonials and case studies — AI fabricates specifics that can damage trust.

Our recommendation

Use AI for structure and initial copy. Edit the executive summary to include specific knowledge about the client's business. Write the pricing section yourself. Add one real case study. This hybrid approach takes 20 minutes and outperforms pure manual writing.