Virtual Goods
Inside Virtual Goods: U.S. virtual goods market to hit $2.1 billion in 2011; http://j.mp/b0YtUe
The virtual economy of Second Life reaches an all time high of US$ 160M in Q1/10; http://j.mp/9HZfHQ
PlaySpan survey: The most popular virtual goods are virtual money, weapons, gifts; http://j.mp/oJkbz