What's the biggest assumption you've ever made about a startup idea?

What's the biggest assumption you've ever made about a startup idea?

Mine was thinking:

"If people say it's a good idea, they'll probably pay for it."

Turns out those are very different things.

The more founder stories I read, the more I notice that startup failures often trace back to assumptions that were never tested:

• Customers have this problem
• The problem is painful
• They'll switch from their current solution
• They'll pay
• The market is large enough

The hard part isn't coming up with assumptions.

The hard part is systematically testing them before spending months building.

I've been building a tool around that process and it's made me curious:

What's the assumption that ended up being completely wrong in one of your projects?

Author: Professional-Ruin653