Breaking news from John Smedley, President of Sony Online Entertainment, via Twitter:
j_smedley: Free Realms just hit 4M registered players!
For those counting, that's another 1 million registered players in 19 days!
UPDATE: This just in, to celebrate the 4 million mark, from July 2nd to July 8th 2009 players wil receive double the Treasure Tickets! You can use these Treasure Tickets at the Royal Vault in Sanctuary to get cool rewards.