It's the same with your direct mail letter. The first paragraph must contain information they need or want that grabs their attention immediately or your information is destined for the wastebasket. In many cases a question works well. Or you might use an industry statistic. I would probably keep reading to find out what that one thing is and am I doing it wrong.
Every product has a feature or features.
Keep in mind that a feature is what a product has and a benefit is what a product does. One of the most powerful benefits a product can offer is convenience. A handsaw will cut a board but a skill saw can do the same job in one-tenth the time. The convenience of speed outweighs the additional expense of the skill saw. The fact that a car has four doors doesn't mean much unless you can translate that into a benefit to the car buyer.