This is so important that I have put the message in the lecture heading. Product / Market fit is everything and you should not even consider making any significant investment in your business until you get this part right.
So, what is Product Market fit I hear you say?
Product Market fit is where you take your product/service to your target market (ideally your sweet-spot) and you get their input on: -
The value you offer and what it means to them
Competitive landscape and if you are missing any points of differentiation between your product and your competitors products
Value they may see which you have not focused on in your messaging
A true product/market fit exercise bridges the gap between you thinking you have meaningful value to offer and potential customers telling you that you have something they would buy.
This validation is critical especially if you are a product finder with limited marketing experience in that it bridges that gap between having a great cool product and a marketable product you can build a real business around. Ultimately, you do this to backup your gut feeling on how big your product or service can be