Gotta Have My (Barbie) MP3

Digital music players are hot—even with the lunchbox set: A recent study shows 31% of 6 to 10-year-olds use them. This means a whole new market for kid-themed players, accessories, music and video, reports Advertising Age. Indeed, players aimed at children have proliferated in the past two years. “They have a whole wall of them in Toys 'R' Us," said one researcher.

Parental hand-me-downs, lower prices and more choices may account for the growing number of young users. An analyst suggested advertisers who want to exploit this new market adopt a positive angle for kid-targeted products, such as including smaller headphones with limits on volume and age-appropriate music. Apple already lets parents limit the volume on their childrens' players. (More portable media players stories.)