Facebook has halted plans to launch the social-networking equivalent of Google’s AdSense network, according to a new report from AllThingsD. As originally envisioned, the Facebook advertising network would have posted ads on other developers’ mobile apps and Websites. It’s assumed that such a network would leverage Facebook’s massive store of user data in some way. “We are pausing our mobile ads test off of Facebook,” a Facebook spokesperson emailed the publication. “While the results we have seen and the feedback from partners has been positive, our focus is on scaling ads in mobile news feed before ads off of Facebook. We have learned a lot from this test that will be useful in the future.” AllThingsD’s unnamed sources attributed the pause to concerns “that Facebook isn’t ready to deliver ads on external sites that produce significant value for either the network or its partners.” Although it continues to reign as the world’s largest social network, Facebook faces significant competition from the likes of Twitter, Pinterest, and Google+ for users’ attention. Instagram, the photo-sharing service that Facebook purchased earlier this year for $1 billion, recently disabled photo integration with Twitter; a short time later, Twitter launched its own photo service, complete with Instagram-style filters and editing tools. Meanwhile, Google claims some 135 million users head to their Google+ activity stream on a regular basis, while some 235 million actively engage with Google+ features baked into services such as Gmail and the Google Play hub. That’s more than enough competition for any company to face; and just to make things that much more interesting, Facebook must also deal with Wall Street investors anxious to see its stock price rise. And given how people are increasingly interested in using tablets and smartphones in lieu of a PC, the path to bigger revenues goes through mobile; the only question is how Facebook can monetize its presence in that area.   Image: Annette Shaff/Shutterstock.com