Hi Dave!
The way the payment system works is that any order for which payment has not yet been finalized is held in a separate area for "pending orders," and only once payment is received the transaction considered complete, it's merged with the normal orders and the so-called "fulfillment" contents become available (information email, game).
With regard to direct transfers they say "up to five days," but that could also mean it could happen more quickly depending on the financial institutions involved. The idea is if it's been more than five business days, then you should contact me and I can check what's up. (This is unlikely, but you never know.)
They can't fulfill the purchase immediately since in theory something could either go wrong with the payment, or a customer can cancel a transaction while it is still being processed (i.e. before it reaches its destination).
Hope that helps!
