Am I reading that right? On Internet purchases, 10 minute delays are unimportant? I chose who to buy Cisco routers from because of the specter of a 5-minute delay. Can you flesh that statement out a bit?
Essentially that the shipping time utterly dwarfs the validation delay. The main place this wouldn't be true is if you purchase an online activation key of some kind - if you purchased a downloadable, it'll often still take more than 10 minutes to complete.
The moment you send out your transaction (assuming it's valid), you can consider it approved, and move on with your life. The recipient can also acknowledge the transaction within a minute or so at most, it's the network validation and protection against alternate transaction histories that takes time.