This executive purchased Tumblr.  
Martin Sorrell, CEO of the ad agency WPP, once publicly called this CEO out for not returning his emails.  This CEO poached Henrique de Castro and runs weekly FYIs with employees at URL's ("Earl's"), the company cafeteria.  Instead of discussing a new ratings policy at a Q&amp;A session, this person read aloud the children's book Bobbie Had a Nickel.  This person gave a lucrative new contract to "global anchor" (*) Katie Couric.  The release of the company's first mobile mail client was almost delayed when this person demanded the color scheme be changed to purple at the last minute.  This executive purchased Tumblr.  Eric Jackson valued this person's company at negative 4 billion dollars when you subtracted its lucrative investment in Alibaba.  She succeeded CS-degree forger Dan Loeb after leaving Google.  For 10 points, name this CEO of Yahoo.
Martin Sorrell, CEO of the ad agency WPP, once publicly called this CEO out for not returning his emails.  
Marissa Mayer