With the popularization of the Internet also came the popularization of the idea of the "free-to-play" game - a game that had no initial cost to its players. Essentially free to play, these games earn money through donations and, more often, microtransactions, small purchases designed to enhance the quality of gaming for the player.
Some of the most popular free-to-play games are massively multiplayer online games (MMOs), and are often called F2P for short. Popular free-to-play MMOs include "Runes of Magic," "Vindictus," and "Forsaken World."
Other popular free-to-play games are social games, often played on Facebook. Popular games here include "FarmVille," "Zuma Blitz," and "Pet Society."