Virtual currencies come in many shapes and sizes, from Bitcoin to Amazon Coin. The gaming industry has a whole subset all of their own. Within World of Warcraft there are multiple virtual items available for sale. In order to purchase these items, players are required to use the in-game currency Gold, which can be earned, purchased, or received as payment for items sold at the Auction House. As of November 2015, the online game had over 5.5 million subscribers.