I agree with monsterer. Charging for ideas is hard. You first have to tell customers one idea. If they like the idea what will stop them from using it without paying? NDAs are not worth much in court.

I don't know if you are familiar with the lean startup method.

The method states that you should treat your startup (project, idea, etc) as an experiment. You should come up with a hypothesis and then test that hypothesis with some good metrics to see how your new feature was received by the users and iterate the process quickly, but of course, with some quality to it.

So I do not agree with this guy.

I think, if you have an idea and you have a way to measure the response of the users to your new idea, you should go for it. You should test the idea with a minimum viable product that way if the idea does not receive good reviews from the users you did not waste much time on it. If the users like it, then you can develop it further.

This looks like a great project and I wish you the best!