Yahoo has just announced that they have completed the acquisition of popular blogging platform Tumblr – a deal that was set into motion back in May. Yahoo reportedly payed $1.1 billion for Tumblr, in cash. For a comparison, that’s just a little more than Facebook paid for Instagram last summer.

As we already know, Tumblr is set to help modernize Yahoo, and Yahoo is set to help Tumblr with advertising (among other benefits of the partnership, of course).

The deal offers unique opportunities for both companies. Tumblr can deploy Yahoo!’s personalization technology and search infrastructure to help its users discover creators, bloggers, and content they’ll love. With more than 50 billion blog posts (and 75 million more arriving each day), Tumblr can bring complementary content to Yahoo!’s media network and search experiences. Yahoo! will support Tumblr’s efforts to create advertising opportunities that are seamless and enhance the user experience.

“Tumblr is an incredible company. I’m thrilled to officially welcome David and his team to Yahoo!,” said Yahoo CEO Marissa Mayer.

Though Tumblr CEO David Karl expressed his immediate elation with the acquisition (if I recall correctly, the response was “F*ck Yeah!”), not all Tumblr users shared his excitement. There was quite a bit of backlash, including hundreds of thousands of signatures on an anti-Yahoo petition.

From the beginning, Yahoo has promised that Tumblr will remain independent. Yahoo reiterates that pledge today with the news of the finalized acquisition.

“We are beyond excited to partner with Marissa and the wonderful team at Yahoo! that we’ve already come to know well. Their support and belief in our vision gives us an opportunity now to be the most ambitious we’ve ever been,” said Karp.