martphone penetration in the world’s top 19 digital markets is expected to double from 35.5% last year to an average of 71.7% in 2015, according to a new media forecast published by ZenithOptimedia. While tablet penetration in these markets will lag that figure, adoption should reach 13% by 2015, up from just 4.7% last year. That number should vary substantially among the different markets: recent reports have put tablet ownership in the US at about 25%.

via Smartphone Penetration in Top Digital Markets Set to Double by 2015.