Not to argue but there are numerous benefits to sealing asphalt properly. You're right about not re-sealing until the old sealer is wearing off (usually several years). But I must disagree with the advice about the white stone. Asphalt should be sealed when it starts to fade from that new black color to a dark gray. Sealers need the asphalt binder to adhere properly. If the asphalt cement is worn or weathered completely to where the stone itself is showing the sealer will not adhere well and will wear prematurely. Sealing asphalt is comparable to painting wood. Nobody would think of waiting until new wood was showing weather damage before painting. Sealing will protect new asphalt better before the damage of ozone, de-icers, etc. ever starts.