On April 28th, Guild Wars will be celebrating its 4th anniversary.  Since its launch in 2005 the game has sold over 6 million copies.  NCsoft has attributed the games success to their subscription free business model.

In celebration of its 4th birthday, and all of its success, characters turning four on April 28th will receive a special gift in their inventory.  In addition to this, two popular arenas, Dragon Arena and Rollerbeetle Race, will be reopened today.

Source: GamesIndustry, NCsoft