I used it to setup automatic payments and such. Don't like having to think about that stuff and worry about mailing checks in...just let them take the money. I wouldn't recommend this if you don't have extra cash in your accounts.
I use it frequently to log in my service records as well as all the modifications I've done to my car. It's also a good place to go if you have stuff done to your audio system and you forget your radio id. I thank Honda for setting up this owner link for us. Good job HoA!