• by Mark Walsh  @markfwal, December 2, 2013

Tumblr on Monday introduced a new ad unit that will allow marketers to run messages in the section showing what’s trending on its mobile app. The new native format -- Sponsored Trending Blog ads -- will appear in the stream of updates highlighting content from top-trending blogs and will feature a dollar sign icon in the corner to set them apart from other posts.

Trending Blogs, which Tumblr launched in July, is found under the “Explore” tab of the company’s iOS and Android app.
 
The new ad unit is the fifth the Yahoo-owned social-blogging service has launched to date, and the second mobile ad product. Earlier this year, it added Sponsored Web posts, which run in a user’s “dashboard,” or news feed, for the desktop as well as mobile. It also offers ad placements within its curated Radar and Spotlight sections.
 
Similar to Twitter’s Promoted Trends, Tumblr’s Trending Blog ads give marketers prominent placement among most popular content on the site that day. Advertisers can customize the three posts displayed, with any clicks (other than on the “Follow” button) leading to a brand’s Tumblr blog.
 
The initial group of marketers testing Sponsored Trending Blog ads includes beta partners Turner Broadcasting, Delta Air Lines, Twentieth Century Fox, Calvin Klein and Sony Pictures Entertainment. The first ad, promoting Fox’s Jan. 17 release “Devil’s Due,” debuted today as part of a soft launch before a broader 2014 rollout.
 
Sony plans to use the ads starting on Thursday as part of its trailer launch for the "Amazing Spider-Man 2." The studio runs a Tumblr blog dedicated to the franchise called The Daily Bugle.  
 
For Yahoo, the move reflects its intentions to gradually ramp up advertising on Tumblr without alienating its users in the process. Following its $1.1 billion acquisition of the startup in May, Yahoo CEO Marissa Mayer said the Web giant would look for ways to integrate advertising along with search tools and content management to boost Tumblr’s growth.