The most common method of monetization is to sell an entire game for a single purchase price. Furthermore, game publishers sometimes release game expansions that provide new game material for a set price. As digital streaming has grown in popularity, downloadable content (DLC) has emerged, and can include major new expansions or minor content updates for a set price. New monetization tactics have emerged as games have become more online, multiplayer, and planned to last forever. Subscriptions are required for certain titles, which enable players to pay a subscription charge to access the game servers. Other games use a free-to-play format, in which players can play a portion of the game for free before buying additional content that increases the overall experience. Microtransactions are used to buy premium content in small, bite-sized pieces. This microtransactions may have either permanent or consumable material, and can be used only once before having to be repurchased. Many different variations of these multiple monetization techniques have been attempted in sports. Microtransactions are now the primary way of charging for online games, and for many major corporations such as Zynga and Nexon, they are the only method of direct content selling (excluding secondary sales sources such as advertising). In contrast to a one-time fee or subscription, microtransactions include the selling of unique virtual products or services. Hundreds of microtransactions are typically available to gamers in each book, and in most scenarios, they can be used to improve a player's chances of completing game goals compared to others who do not buy these microtransactions. The word "pay to win" was born as a result of this and these games are described as "free to play" for those who do not wish to pay.