It's beginning to look like Facebook might spoil Yahoo's acquisition party. 

The search giant has been eyeing Tumblr for awhile, according to All Things D, and CEO Marissa Mayer has been on an acquisition spree--ten companies to be exact--ever since she took the reigns nine months ago.

According to sources close to the corporate development team, Yahoo believes Tumblr could bring them the key 18 to 24-year-old demographic it needs to seem relevant and youthful. 

However, David Karp, one of the blogging platform's founders and chief executive, has been seen around Silicon Valley nuzzling up to another tech bigwig who goes by the name of Mark Zuckerberg.

Karp was first spotted at the Facebook Home launch, reports Giga Om. Facebook also has a reputation for snapping up startups, with Instagram being its largest (and most successful) to date.

A Facebook spokesperson declined to comment, but Giga Om seems to think both companies are eyeing Tumblr due to its mobile ad push. Mayer has said she's focused on mobile, and Tumblr owns nearly 108 million blogs and 50 billion posts, with 117 million visitors a month, according to comScore. Karp's company is rumored to be valued at $800 million. 

"For Yahoo this could be a much needed foray into mobile advertising and also into pushing new native ad-formats that help diversify its ad business away from the usual web advertising," says Giga Om.