If you want to market a product, a service or an invention, you need to ask yourself why anyone would buy it. What's in it for them? Will they buy it because it's got all sorts of cool technology? No. They'll buy it because it fills a need.
Last night I gave a presentation on marketing to IACT - the Inventors Association of Connecticut. One of the points I really focused on was the concept of the benefit. What's a benefit? In pain relievers, it's relief and being able to get on with your day. For a business person, it's probably increasing the bottom line. Think about all the products you use. Why do you use them?
Now, think about the product you want to sell. Why would anyone want to use it, let alone spend money to buy it?
Understanding your key benefits is one of the first steps in developing effective marketing and in developing a winning business plan. Remember -- people buy benefits, not features.