"Give one, get one" Marketing Strategy - is it new or has it been used in the past?

[AgaBoogaBoo]

http://laptop.org/ has the $200 laptop and began using a "buy one, get one" strategy. This shoe company has been doing just the same: http://www.tomsshoes.com/

Is this a new, unique idea, or has it been used in the past? It seems to me like it could have a lot of power.