Both Marissa Mayer, Yahoo's chief executive, and David Karp, Tumblr's 26-year-old founder, reassured worried users on Monday that Yahoo's deal to acquire Tum...
Yahoo! Approves $1.1B Tumblr Acquisition
The Yahoo-Tumblr Deal: Why They Paid $1.1B
YAHOO BUYING TUMBLR
President Obama's Tumblr Q&A at the White House
Yahoo buying Tumblr for $1.1 Billion