How much is your favorite website for .gifs, memes, quotes, diary entries, abstract photos (nudes too) and more worth? According to Yahoo! it’s worth $1.1 billion in cash.

With a B.

And Ben Franklins.

The search engine made it official Monday morning, obtaining Tumblr for the ludicrous lump sum but making sure everything that Tumblr already has in place from its mission to its CEO David Karp stays the same. Newly minted Yahoo CEO Marissa Mayer announced the acquistion on her own Tumblr while Karp announced the move on the Tumblr staff blog. So why shell out that kind of money for a company whose worth was raked in $15 million in revenue as of a year ago? “The combination of Tumblr+Yahoo is expected to grow Yahoo’s audience by 50 percent to more than a billion monthly visitors, and to grow traffic by approximately 20 percent.”

“Tumblr is redefining creative expression online,” Mayer said. “On many levels, Tumblr and Yahoo couldn’t be more different, but, at the same time, they couldn’t be more complementary. Yahoo is the Internet’s original media network. Tumblr is the Internet’s fastest-growing media frenzy. Both companies are homes for brands — established and emerging. And, fundamentally, Tumblr and Yahoo! are both all about users, design, and finding surprise and inspiration amidst the everyday.”