It doesn't seem like it was that long ago that the entire concept of people spending real money on virtual items and currency was just bizarre. The first mentions of such a thing this writer ever came across were back in 2003, when Julian Dibbell told the story of Black Snow Interactive, rumored to have been operating virtual sweatshops operating in Mexico. Fast forward to 2009 and the notion of shelling out real world cash for the ephemeral has become commonplace. Moreover, these formerly arcane business models centering around virtual trading have ballooned into a huge business, much to the chagrin of many game companies and their players. However, not all companies attempt to fight this ever-increasing gravity of real money trading (RMT) that now permeates the MMO and virtual worlds industry, and some seek to make it an aspect of their business that they control rather than something they need to curb. Indeed, the profits of many (legitimate) businesses are largely derived from sales of virtual goods, as Rory Maher explains at paidContent.org in his article titled "From Pet Penguins to Flame Throwers: The Biggest Sellers In The Virtual World".
Maher looks at three companies doing well for themselves in the virtual goods game, and what they're selling that's proven so popular. He points out Tencent, a Chinese IM provider that incorporates microtransactions into the service, allowing users to spend their "QQ" currency to enhance and customize their IM interactions, even buying virtual pets that exist on their desktop and run around inside their instant messages.
Playdom is another company Maher mentions that's focused on social gaming, the operators of popular MySpace games like Mobsters. He writes that roughly half of Playdom's revenues are derived from promotional offers where users fill out surveys in exchange for virtual currency given by the sponsoring brand, in addition to upgrading weapons, gear, and even paying to skip levels in the Mobsters titles.
Maher's virtual goods trinity is rounded out by Zynga who also operate in the social gaming sphere, providing users with games played across various social networks and even the YoVille virtual world, as well as a host of virtual items usable in these games and spaces.
Have a look at "From Pet Penguins to Flame Throwers" for a closer look at some of what paidContent.org identifies as the top selling virtual goods out there.
