Few things in life sell themselves. Ice cream, holiday cards for mom and maybe movies about mopey adolescent vampires. But in general, to sell a product you need a sales pitch. You need an angle. You need an idea.
Say you want to sell umbrellas. Great products, considering they keep you dry, can be imprinted beautifully in dozens of different ways and generally have a high perceived value. You can't take that information alone to a client however, and expect a sale. "Hey, check out this umbrella! It's neat and, uh, umbrellas! They stop rain!" isn't exactly going to have product flying off the shelves.