When Yahoo CEO Marissa Mayer bought Tumblr for a cool $1 billion in 2013, she pledged “not to screw it up.” Two years later, it’s become apparent that Yahoo has failed on that promise. Today (July 18), the beleaguered tech company said it took $482 million in impairment charges for the blogging platform in the…

via Marissa Mayer promised “not to screw up” Tumblr, but she totally has — Quartz