As stated above, sadly you can't. The 4-pack includes 1 copy that goes right to your inventory, and 3 other copies go to your inventory as giftable. Sort of Valve's way of preventing folks from stocking up on sales like this and selling off/trading off or what have you with the games.
I worked around it, though. First, create a mule account for yourself on steam, verify the email and sign up for the community. Then, get a hold of a friends Steam account, send a friend request to your mule account, and buy the 4-pack on it (You'll have an option to opt out saving your credit card, in case you have snakey friends). That account will get a copy in it's game library, and the 3 gift copies that go into the inventory can be sent to your mule account after accepting the friend request on the mule from your friend's account.
From there, go ahead and distribute the games, just have your buddies add the mule account as a friend, as for whatever reason I couldn't make friend requests on the mule account without buying a game on it.
Hope this helps, bud. I bought two 4-packs for GoIO by doing this. Cheers.
