From the Article, "Free massively multiplayer online (MMO) games are abundant these days, but the free part is often deceptive. Yes, the games can be played and enjoyed without breaking out a credit card but many feature a premium shop filled with exclusive little goodies.
In some cases cash, shop purchases will allow players to customize their character or items (weapons, pets, etc.) bought from the shop can make adventuring a little easier. In the case of Mabinogi, for example, certain shop purchases even allow players to participate in special quests and storylines.
So I decided to take a look through the premium cash shops in some of Aeria's, Nexon's and Ntreev's games and determine just how much fun $10 can buy in some free MMOs."