What you are really doing when sending money to a book is transferring the money from your Neteller account to the Book's Neteller account. If the book needed to get the money transferred to their bank, they would face similar delays.
thanx for the responses guys....it kinda makes sense, except if someone is depositing money into their NT account via credit card, why can't they send money to someone right away? I don't get why a cc won't go thru right away....