The main concept of this book https://amzn.to/3e08Ryz is perhaps invaluable to anyone bringing a product to market and is something I find myself discussing with lots of startups I have meetings with. Without giving it all away buy and read the book – using my link! – there is a fundamental difference between those who are happy to try and test your product and the large numbers you want to buy it. An Angel investor friend of mine calls it the 200 problem. There are roughly 7000 GP practices and you can getting up to 200 to test your product is one thing getting the others to buy it – where the real money is – is different.