Forecasting can be a tricky business. Every so often, a truly paradigm shifting event occurs that requires a wholesale re-think of how emerging markets will develop. Such is the case with Facebook Zero – a stripped down version (no pictures, videos, etc.) of the social network offered to non-data subscribers in emerging markets for free at 0.facebook.com.

It has been reported, and our newly updated draft social networking forecast (to be published in July) confirms that about half of all page views on the mobile web are social networking related. Facebook Zero should tip the balance further in favor of social networking in emerging markets.

The impact of the 50 carrier, globally supported Facebook Zero will be huge for users, carriers, and competitors.

1. Locking users in. Using its size, Facebook has been able to negotiate deals with carriers that other social networks or start-ups will not be able to rival. As individuals, their friends, and their families sign up for the free service the network effect will take hold and position Facebook as the de facto social network.

2. Reach. According to Strategy Analytics’ Global Smartphone Sales Forecast by Country: Asia Pacific & Emerging Markets and the Worldwide Cellular User Forecasts, 2010-2015, the number of mobile users in India in 2009 was 389.9m with just under 6 million smartphone owners or 1.5% of the mobile population using a smartphone. While not all these non-smartphones millions more users will have access to Facebook now than in the past expanding Facebook’s reach exponentially. And India is just one of the dozens of countries being deployed to (see chart below for the rest).

3. Advertising. A key revenue driver will be advertising. Facebook will have a sticky user that relies exclusively on its service to share personal information and location data which is necessary for targeted advertising to hundreds of millions of users in emerging markets. However, if carriers are not sharing in the revenue opportunity they risk missing out on the more than $7b in browsing revenue associated with social networking in 2010, according to the Global Mobile Social Networking Forecast 2006-2013.

4. Data Upgrades. While many users in emerging regions may not be prepared to sign up for data services yet, enticing users by showing what the mobile web offers with a stripped down version of Facebook could be a sufficient appetizer to winning their business in the future.

5. Boxes out competitors. The very hot mobile social networking space, which we have analyzed Here, Here, and Here will be owned by Facebook in emerging markets if Facebook can effectively roll out its geo-location it has touted. Facebook has just went from the 800lb gorilla in mature markets to the 2 ton gorilla

The service is also important for Facebook which has recently been banned in Pakistan and faces competition from feature phone staple – text messaging which serves as a crude social network in some emerging regions. What this means for partners – be it carriers, content owners, advertising networks, or others – is that Facebook is the partner companies will need to work with to immediately reach into emerging markets.