New ad networks leverage Facebook's long tail

Let's say you've got a great new Facebook app or widget. Good for you! Too bad no one is going to see it.

Narendra Rocherolle (and a few other entrepreneurs) are trying to rescue your app. Rocherolle launched fbExchange a few months ago with the goal of making the "long tail" of apps work for developers. The idea is that you put a little ad banner on your page, which other apps are pitched on. In exchange, your app gets advertised on other Facebook apps.

You can buy clicks if you have no traffic to feed into the network. You can also sell your advertising space outright if you don't want to participate in the click-for-click exchange.

All ads are single-line text blurbs that run at the top of Facebook app pages. Coming soon (possibly this week), fbExchange will be adding new advertising units.

I like this model. You can pay if you need traffic. You can charge if you have it. Or you can go freebie if you have some and need a bit more.

Other startups are working on Facebook advertising networks. Apps developer Hungry Machine is launching its ad network this week; the founders just showed me a demo of the analytics engine, which looks very strong. Lookery is also in the process of launching, and although the site is live, it wins my new Webware Mud Award--you can't really tell what the site does until you log in (and not much then, either). But trust me: It's an ad network. See also Social Media, which works across social networks; RockYou, which operates several successful Facebook apps; and Cubics.

Rocherolle is up to more with fBExchange than just ads, though. He's hoping to create a data exchange, where one site can grab social network information from another, to build mashups. The data Rocherolle is hoping to help companies expose even Facebook doesn't have. For example, if you subscribe to a recipe app on Facebook, Facebook's servers will know that you use the app and which of your friends use it, but Facebook won't know which recipes you like, since that data is store on the app's servers, not Facebook's. Rocherolle wants to help create an exchange for this data. Hungry Machine's execs also pitched me on a similar vision; they said they hope to use cross-app data to more effectively target their ads.

There is a chance that Facebook itself might launch an ad program that competes with these companies, but in the meantime, Facebook developers looking to make a few bucks--or get the traffic they need--might want to experiment with these new networks. Advertisers should get onboard soon, too. Getting experience with Facebook advertising is cheap right now. Rates are sure to go up as the platform matures.