Some 8 million US kids and teens spent time in virtual worlds on a regular basis last year, according to eMarketer, which expects that figure to grow to 15 million by 2013. The market research firm estimates that 37% of kids 3-11 play in virtual worlds at least once a month, and 54% will by 2013. According to conference organizer Virtual Worlds Management, as of this past January, there were 112 … [Read more...] about Kids’ virtual-world numbers: Update