As the virtual goods market continues to grow in the US – nearly doubling this year to just over $1 billion, according to our recently released Inside Virtual Goods research report – more attention is being paid to one of the more intriguing sectors of the virtual goods payment ecosystem: offers. Offers, a form of incentivized lead generation for performance marketers, are a popular alternative payment method for a variety of free-to-play online games, and currently play a role in the monetization of many social games through virtual currency microtransactions. How does it work? Basically, players are incentivized by developers to take advertiser offers with in-game virtual currency that they can then use to progress through the game.