This is a good question. And you are right: the first "golden" rule is always held to be "build something people want". I haven't looked at this quantitatively

This is a good question. And you are right: the first "golden" rule is always held to be "build something people want". I haven't looked at this quantitatively - I think it would an interesting study - but I wonder how many businesses started out building something that people already wanted, or instead built something that people didn't know they wanted. I reckon that a lot of products, particularly in technology, fall into the latter group. So don't despair. As Michael Dorfman says: you have to be able to quantify either a) how much your product will increase revenue, or b) how much it will save in costs/overheads. If you can't do this you wont be able to sell your product - even if it's free. The overhead in learning a new technology will not be deemed worth it. Even if you can quantify the value of your product, you still have to fight inertia. As you are discovering businesses have established ways of doing things. It might cost them a lot both in time and money to switch to a new way of doing things (a factor you'll need to consider in the ROI your product offers). Additionally an even bigger barrier to change is contractual relationships with suppliers, buyers and staff. So even if your widget is half the price and twice as good, if the customer is locked into a three year deal with another supplier they are not going to buy it. You really need to understand your target markets' motivation for doing things the way they do them now, and the value that they derive from this. The value they see might not be the value you imagine - and if your products value is not aligned with this, it's going to be difficult. So talk to your market, find out exactly what value they derive at the moment, assess how your product aligns with this, and how much it will cost them to change. Then value your product.