Watch out Google, Facebook ads appear on Zynga.com

Google jumped into Facebook’s territory when it launched its Google+ social network last year. Now Facebook seems to be jumping in to compete with Google in the advertising space. External ads from the social network are appearing on Zynga.com — the first of their kind outside of Facebook’s own domain.

“People may now see ads and sponsored stories from Facebook on Zynga.com,” said Facebook in a statement to VentureBeat. “We don’t share any information about people or advertisers with Zynga and advertisers do not have any new targeting criteria.”

The advertising appears once you’ve logged into Zynga.com with your Facebook account. It is otherwise unavailable. The ad I found appeared in the lower right hand corner, under my list of friends online and showed my friends who “liked” that brand and had a “sponsored”  tag with the Facebook ‘F’ next to it. Zynga and Facebook have an advertising revenue share set up.

Facebook did disclose an agreement between the two companies after Zynga filed an amendment to its S-1 filing in 2011. It told Inside Facebook that it had promised to help Zynga with external advertising in the future. At that time, the social network didn’t reveal timing for the new advertising. The appearance of Facebook ads on Zynga.com does, however, make it seem possible that a home-grown Facebook ad network is on its way, even if it’s not immediately obvious how it will work.

Advertising is Facebook’s lifeblood and the ability to expand beyond walls and news feeds is a huge opportunity to take revenue away from Google. Google runs its own ad programs, such as AdSense and AdWords specifically for advertising on its search engine. Rumors also say that Facebook may decide to compete with Google in search too.

An image posted by Mark Zuckerberg (see right) soon after the company announced its intentions to go public stirred these theories. The picture showed Zuck’s laptop with Facebook pulled up. At the top of the screen was a long, thin, white bar that greatly resembled a revamped search field. Altimeter Group analyst Rebecca Leib told VentureBeat at the time that she thought a Facebook search product could “have not only very tangible advertising benefits for Facebook, but also make Facebook a more compelling place for users.”

While no such search has yet been revealed, it’s safe to assume that Facebook will be competing with Google more deeply in the near future.

hat tip Inside Facebook