Suppose, you want to buy a new car. You go to showroom and have conversation with sales rep. He explains features like engine power, leg space, accessories provided with the car. It looks really appealing. So, you make decision to buy.
You have already assumed that you will get all features in the car, just as sales rep described to you. Stated commitments form core part of the product/service – just as what is described in manual or website.
Let us assume that the car breaks down in second week itself. You go to same showroom and ask for service center. You get a shock of your life when sales rep comes to you and says,”Well, we do not have any service center. You did not ask for it earlier.” Unstated commitments are just like this – Customers never state it clearly. They are like subtle cues which provider has to figure it out.
Unstated commitments are no less important. Afterall, will you buy a car with no service network, even though it meets all the stated requirements ? Will you buy software which is not secure?