World of Warcraft was first announced by Blizzard at the ECTS trade show in September 2001. Development of the game took roughly 4–5 years, and included extensive testing. World of Warcraft requires a subscription fee to be paid to allow continued play, with options to pay in one month, three month or six month blocks, although timecards of varying length are available both online and from traditional retailers. Expansion packs are also available online, and are also available from traditional retailers. As the game client is the same regardless of the version of World of Warcraft the user owns, the option to purchase the expansion online was added as it allowed for a quick upgrade.
