Why seal an asphalt driveway?
It is very important to use an asphalt sealer on your driveway to prevent damage caused by sunlight, rain, and snow. A new, unsealed driveway will be fine for a few years, but neglecting to apply asphalt sealer to the surfaces of your property allows water to sneak beneath the porous surface. When the water freezes, heats up, or saturates the soil underneath the pavement, you will start to see cracks. Your only choice at that point would be relaying the asphalt.
Driveway sealing also helps maintain the original, dark color of your driveway. The sealer will keep your asphalt black, rather than letting sun and traffic dull it to a faded gray. Asphalt sealer can also resist spills from car oil and other maintenance fluids that you don't want to stain your driveway.