Blizzard provided a plethora of data points about the World of Warcraft series in a massive infographic. The 100 million number includes the creation of trial accounts, and covers players in 244 countries around the world. As of the end of September 2013, Blizzard counted 7.6 million active subscribers to World of Warcraft. More than 500 million characters have lived on those 100 million lifetime accounts, with a faction breakdown of 52 percent Alliance, 47 percent Horde and 1 percent neutral.
Daily activity remains high in Azeroth, according to the infographic. Every day, World of Warcraft players partake in 3.6 million pet battles, 900,000 player-versus-environment instances, 600,000 player-versus-player battles and 2.8 million trades in the game's Auction House.
You can see the full infographic on Battle.net.