The article seemed a little misguided at what a social network is. I think the idea has awesome potential - think about a live display that has all the information you could gather if all the vehicles on the road were equipped with dash. You could come up with some fantastic and useful displays. It said the guys were keeping the API open, which leads it in that direction. And they make money for each sale: a good solid business model. I predict success for this company.
Depends. If only one in every ten thousand cars has it, then it's not very useful. If one in every four cars has it, then you're getting a lot of useful information about traffic.
In the meantime, they can make it useful in other ways, perhaps getting real-time traffic feeds from servers, as it hinted it did, and as that feature attracts a user base, they can make it even more attractive by adding features that utilize this network-effect.