SAN FRANCISCO — Yahoo is buying online blogging forum Tumblr for $1.1 billion as CEO Marissa Mayer tries to rejuvenate an Internet pioneer that had fallen behind the times.
The deal announced Monday is Mayer's boldest move since she left Google 10 months ago to lead Yahoo's latest comeback attempt. It marks Yahoo's most expensive acquisition since the Sunnyvale, Calif., company bought online search engine Overture a decade ago for $1.3 billion in cash and stock.
Yahoo is paying mostly cash for Tumblr, dipping into what remains of a $7.6 billion windfall reaped last year from selling about half of its stake in Chinese Internet company Alibaba Holdings Group. Taking over Tumblr will devour about one-fifth of the $5.4 billion in cash that Yahoo had in its accounts at the end of March.
While hailing Tumblr as a fount of creativity that attracts 300 million visitors each month, Mayer told analysts Monday that she is "making a sincere promise to not screw it up." David Karp, a high school dropout who started Tumblr six years ago, will remain in control of the service in an effort to retain the same "irreverence, wit and commitment to empower creators," Yahoo said.
Karp, 26, may now have a managerial mentor in Mayer, 37. Tumblr, which will remain based in New York, has about 175 employees while Yahoo has 11,300 workers.
Mayer, who worked closely with Google co-founders Larry Page and Sergey Brin during her time at the company, had high praise for Karp during Monday's conference call. "David Karp is one of the most inspiring, insightful entrepreneurs that I have ever met," she said.
In his statement, Karp predicted Yahoo would help Tumblr grow even faster as he strives "to make the Internet the ultimate creative canvas. "
The deal is expected to close during the second half of this year.
Tumblr will now play a pivotal role in Mayer's attempt to reshape Yahoo. To take on the challenge, Mayer ended a highly successful 13-year career at Google, which she helped surpass Yahoo as the Internet's most influential company. Since coming to Yahoo, Mayer has concentrated on improving employee morale, redesigning services and bringing in more engineering talent through a series of small acquisitions that have collectively cost less than $50 million.
Yahoo will still focus on mostly small deals, Mayer said. She seized the opportunity to buy Tumblr because she believes the service can accelerate her efforts to turn around Yahoo.
"Tumblr is a game changer," Mayer assured analysts.
As popular as Tumblr has become, the service remains unprofitable. That is likely to raise questions about whether Yahoo paid too much in Mayer's zeal to gain control over a hot service. Facebook Inc. faced similar doubts last year when it bought Instagram, a rapidly growing photo sharing site, that also hadn't been trying to make money. Facebook initially agreed to pay $1 billion in stock for Instagram, but the value had fallen to $715 million by the time that deal closed. Facebook still hasn't proven it will be able to make money off of Instagram.