Aha moments to build a new product?

1) Knowing that the current product is still incomplete, users continue to use it and actively provide suggestions. 2) When you offer a free version but users actively request a paid subscription.

Those are definitely great signs that you've hit on a winning product idea! When users are actively engaged in guiding your development process and requesting paid plans, it shows real demand and buy-in. I'd say it's time to double down on building out those most requested features and getting a premium offering ready to launch. The organic pull from your user base is the best validation you can ask for at this stage.

When users start mentioning your product to their friends and colleagues without prompting - that's when you know you've built something people love and find truly valuable. Word of mouth is the most powerful growth engine.