The first sentence does not explain the rage mentioned in the lead sentence, so the reader has to READ ON to get the explanation. He can subtly point out why the prospect doesn't own one and show how he relates to him. This soft-sell approach works wonders. It tells the reader that the product is not perfect. Depending on the product, it could be happiness, beauty, anything.
All products touch on human needs to either increase happiness or avoid unhappiness.
At this point, it's a good idea to mention that the product will pay for itself over a certain period of time, if indeed that's the case. It's effective because it makes the product look nearly cost-free. Excite people's emotions and hold their interest. Take out any filler material or excessive hype. Find the middle ground, and rewrite the letter.