A good demo can make or break your startup. It captivates investors, attracts customers, and generates buzz. Here’s how to build demos that actually work.

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✅ Good Demo vs ❌ Bad Demo

✅ Good Demo: Tells a Story

• Has a clear main character (your user) with a problem.
• The product solves it and saves the day.
• Every step is necessary to move from problem ➝ solution.
• Leaves the audience satisfied and inspired.

❌ Bad Demo: Gives a Tour

• Moves exhaustively from feature to feature.
• Lacks clear narrative or user perspective.
• Focuses on irrelevant or generic features.
• Leaves the audience confused and bored.

✅ Good Demo: Has a Magic Moment

• Surprises the audience with power + elegance.
• Creates a moment people talk about.
• Drives conviction to buy.

❌ Bad Demo: Forgettable

• Reasonable but not exciting.
• Doesn’t leave a lasting impression.

✅ Good Demo: Believable

• Assumes audience is skeptical.
• Explains how things work with just enough detail.
• Impresses because it feels real and pulled off well.

❌ Bad Demo: Feels Fake

• Vague, hand-wavy, or overhyped.
• Glosses over how it actually works.
• Leaves the audience skeptical.

✅ Good Demo: Tailored to the Audience

• Uses your prospect’s logo, language, and specific problems.
• Feels personalized and thoughtful.
• Connects deeply with the audience’s world.

❌ Bad Demo: Generic

• Filled with acronyms and buzzwords.
• Uses placeholder assets and dummy data.
• Looks like every other demo.

✅ Good Demo: Engaging & Interactive

• Presenter is animated and excited.
• Checks in with audience frequently.
• Encourages questions and discussion.

❌ Bad Demo: Dry & One-Sided

• Presenter lacks energy.
• Pushes forward regardless of audience engagement.

✅ Good Demo: Ready Instantly

• Can be spun up in seconds.
• Easy to repeat across your team or customers.
• Minimal setup and friction.

❌ Bad Demo: Fragile & Tedious

• Requires dev setup or local environment.
• Only works on your laptop.
• Often breaks mid-way.

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🛠️ How to Deliver a Great Demo

• Explain the main character — clarify the role you’re playing and the problem you’re solving.
• Practice end-to-end — record yourself (e.g. with Tella.tv) and refine.
• Rehearse with others — teammates, YC partners, or early users.
• Automate prep — use realistic, tailored data for different personas/verticals.
• Avoid lorem ipsum — fake text breaks immersion. Use realistic content.
• Use a good mic — audio quality matters, especially over Zoom.
• Jokes are fine, but only if they don’t sacrifice clarity or realism.
• Show, then tell — demo the magic first, explain it after.

🧠 Remember: A great demo isn’t just a walkthrough — it’s a story, a connection, and a conversion engine.

credit to yc: https://bookface.ycombinator.com/knowledge/HJ-building-good-demos