Quote Originally Posted by Liquefied
What do you think blizzard would check on the accounts? IP or Name?
This topic has been covered extensively.
http://www.dual-boxing.com/forums2/viewtopic.php?t=2886
http://www.dual-boxing.com/forums2/viewtopic.php?t=2781

There is also information there on how to purchase and activate your accounts (refer a friend) in order to maximize game time per account purchased.