Blizzard have announced that they'll be allowing World of Warcraft players are going to be able to convert their gold into Battle.net credit that can be spent in other Blizzard games.
For a long time, players have been able to spend WoW gold on World of Warcraft Tokens, which allowed players to buy game-time with their gold. Now with the Battle.net credit they'll be able to spend their cash on anything from buying Blizzard games to getting in-game items in titles like Hearthstone or Overwatch.
The WoW Tokens weren't dissimilar to EVE's PLEX currency, but this is a whole approach is nearly unique, allowing players in affect to support their efforts in other Blizzard games but also, they can cash out of WoW in its entirety, taking their effort with them on to another game. Those without a Blizzard authenticator on their account will have a hard limit placed on their maximum balance of credit, and the credits can't be translated into cash.
Developers might be interested to note how Blizzard's continued economics experiments are going, however not many people have the online ecosystem of the games giant.