There are many things in Net 2.0 that are very popular, but that do not necessarily have utility or profitability.
For example, just about everyone and their dog (on the internet, no one can tell you're a werewolf) uses Facebook, and before it MySpace, Friendster, Digg, Reddit, etc. But do these services have a working business model? It seems they all flounder at that point.
It seems to me that most Net 2.0 firms have an unsustainable business model, which is:
1. Get really popular.
2. ???
3. Sell company -> Profit!
In the same way, we know we've got a lot of people who like using their phones to tweet, click, troll, sext, etc. But is this actually useful? And other than the cell phone providers, is anyone making money off this with a sustainable model?