Twitter can gather direct, mass conversation into subject categories like #watermelon, but the conversation is limited by the short form nature of the platform. If longer form methods of online communication could be aggregated into a similar form of direct conversation, it would serve both spectators and authors alike.
For that to happen, citation must be standardized. Current citation methods like hashtags are rarely, if ever, exhaustive, and they often take on the subjective viewpoint of the author or sharer.
Imagine the level of constructive debate and creativity that we might achieve when we organize and bucket all web content into Twitter-like categories. Imagine the kinds of things we might learn about our collective culture.