As you probably know by now, Yahoo is acquiring Tumblr. Why would they buy it if they weren’t going to monetize it?

Tumblr users can expect some ads to be hitting their streams.

“In terms of working together, Tumblr can deploy Yahoo!’s personalization technology and search infrastructure to help its users discover creators, bloggers, and content they’ll love,” said Yahoo CEO Marissa Mayer in her announcement of the deal. “In turn, Tumblr brings 50 billion blog posts (and 75 million more arriving each day) to Yahoo!’s media network and search experiences. The two companies will also work together to create advertising opportunities that are seamless and enhance user experience.”

Business Insider has more from the conference call about the acquisition:

Mayer says that Yahoo released “Yahoo Stream Ads” in May, which take text ads and put them in the news stream on Yahoo.com. She says you can expect more of that on Tumblr. On Tumblr, there is the dashboard, which is like Facebook’s News Feed or inbox. Today, Tumblr does some advertising there. Yahoo would like to “introduce a very light ad load” there. Yahoo also might work with some bloggers who want ads on their blogs. That would only be done with permission. Mayer says the ad units will be native and follow the form and function of Tumblr. She says that you can tell interests of users.

As the animated GIF in Yahoo’s announcement says, “Don’t panic.”

Still, many are panicking. It doesn’t take long to see an overwhelming amount of negative reactions about the deal with a quick “Yahoo” search on Tumblr.com.

And of course, someone has already set up a “Yahoo Staff” parody account under the “Yahoo-Overlords” handle, with the initial post:

hello friends we are excited to ruin your website have a nice day