Advisors have 24 hours in which to deliver an order, after which you may cancel the order at your own discretion. If you choose to do so, your Purple Ocean account will be immediately credited for that order. Sometimes advisors are able to respond right away, and sometimes they deliver the reading closer to the 24 hour limit. It usually depends on their backlog of orders.
If you would like to have your reading delivered within an hour, look for advisors who are available for rush delivery. Rush orders have a 1 hour deadline.