Sony Online Entertainment today announced that more than 20 million users have registered for it's free-to-play online world Free Realms since the games launch in 2009.

To celebrate, SOE are offering every registered member an in-game varsity letterman jacket when they log in to each character, between October 21 and October 31, 2011.

"This benchmark is an honor and a true testament of SOE's success with Free-to-Play games," said John Smedley, President, Sony Online Entertainment. "Free Realms delivers a truly captivating, quality gameplay experience that keeps our community engaged and continues to attract new players every day."

Free Realms is available on the PC and PlayStation 3.