You can enjoy a healthy happy relationship over distance and using the internet as one of the means to keep the connection, but (you know there is going to be a BUT!) unless one of you is going to move closer to the other on a permanent basis, your relationship can not grow and progress as naturally as if you were dating locally.
Long distance relationships allow you to keep up a facade much longer than if someone was seeing you almost daily. Chances are when you do get together with your long distance sweetie, you both have taken time off, cleared your schedules, and are groomed and ready to devote X amount of time to just each other.
Interacting on a daily basis and problem solving together can be so tricky over distance. I've witnessed a friend say one thing to her long distance mate over the phone and after she hung, she rolled her eyes and did what she told him she wouldn't do anyway. "He'll never know," she said. Certainly, this can happen in "regular" relationships, but you are more likely to catch it sooner.