Douglas Rushkoff : Web giant Yahoo bought Tumblr for $ 1 billion to attract young people . He says kids use mobile Web far more than desktop that requires heavier engagement . Comment: Rushkoff : Kids ' tweets about end of an era show challenge of being bought by Yahoo .
Douglas Rushkoff : Web giant Yahoo bought Tumblr for $ 1 billion to attract young people . He says kids use mobile Web far more than desktop that requires heavier engagement . Now that it 's been swallowed , Tumblr risks turning uncool , he says . Rushkoff : Kids ' tweets about end of an era show challenge of being bought by Yahoo .