You no doubt know by now that Yahoo announced that it has agreed to acquire Tumblr for $1.1 billion. Right from the start, CEO Marissa Mayer has said that the company will be looking into putting more ads into the Tumblr experience.

“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,” she said in the announcementl. “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.”

On a conference call Monday, she said we could expect more ads like Yahoo’s “Yahoo Stream” ads on Tumblr, and that they would introduce a “very light ad load” on the dashboard, and might work with bloggers who want ads on their blogs. Ad units would be native.

Well, we might be seeing some new ads sooner rather than later. Tumblr will be launching a test of in-stream ads on desktop users’ dashboards as soon as Tuesday, according to Business Insider, who has obtained Tumblr’s ad sales pitch deck. Here’s the first of a handful of a slides, BI shared:

“With Tumblr’s newest ad product, brands finally are front and center, with the world’s greatest creators,” one of the slides says. “Welcome to the richest content stream in the world.”

According to the pitch deck, the ads will be delivered directly in the native dashboard streams of millions of users. The “Web In-Stream” product is in beta, and Tumblr is offering an exclusive launch partnership opportunity to a handful of select brands for the ad unit’s debut, according to the slides, which say that all Tumblr post types are supported. Partners are apparently being offered category-exclusivity.

For $200K, according to the slides, partners can get ten desktop Radar posts within a 30-day span (between May 21 and July 21), 24 hours each for 5% of all Dashboard page views, support from the Tumblr team, U.S. guaranteed impression serving only, over 25 million dashboard impressions ($8.00CPM on Radar impressions), and multi-week exposure as premier sponsor in Spotlight. They also get ninety-day access to Tumblr Analytics and three weeks as an exclusive beta in-stream launch sponsor partner with ten in-stream posts within a 21 day span (June 1 and June 21).

A lot of Tumblr users are already freaking out.