Are We Seeing The Beginning Of Facebook’s Answer To AdSense?

What’s next for the social network that has 900 million users? An ad network like Google’s AdSense, many believe. And today, InsideFacebook spotted the first hints of what such a thing might look like.

On Zynga.com, the independent web presence of the gaming company whose apps also populate Facebook, users are now seeing Sponsored Stories ads.

Clicking on “Sponsored” takes you to an FAQ page that explains:

When you connect with Facebook on Zynga.com, you’ll see personalized ads and sponsored stories. The Facebook ads you see on Zynga are the same ads you see on Facebook.com.

1. You’ll only see sponsored stories about activity that has been shared with you

2. You can remove ads that don’t interest you by clicking the X

3. Facebook doesn’t sell information that tells advertisers who you are

InsideFacebook notes that the social networking company said last year that it would provide ads on Zynga.com — and share revenue with Zynga — in the future.

Though Facebook said it wouldn’t be showing ads on other sites “at this time,” this is interesting for a few reasons.

First, the Zynga ads apparently only appear for people who are logged in using their Facebook account. Just think of all of the sites that have integrated Facebook Connect — they’re the first sites likely to be brought into any ad network. Heck, even my piddly little personal blog has the new Facebook for WordPress social system — adding ads to that would be easy peasy.

And the data. Oh, the data! There’s everything a person does on Facebook, as well as everything they do on these other sites — including mobile ads. Not to mention all of the interests, demographic info, geographic info, friend connections, etc. that people are giving Facebook.

One big question remains, however. Does Facebook really need any more inventory? It’s already putting its Marketplace ads into exchanges — something it wouldn’t likely do if it could monetize the inventory well itself. Perhaps more volume on highly-sought-after segments would provide value. Or the additional data it could collect could provide value.

Needless to say, one implementation on Zynga.com does not an ad network make, but it’ll be interesting to watch whether this initial toe in the water is successful.