I was just trying to make a point that scarsity and usefuleness are related. In the case of domains the scarcity comes from name recognition and the cost of reg

I was just trying to make a point that scarsity and usefuleness are related. In the case of domains the scarcity comes from name recognition and the cost of registering not just in terms of money, but also in terms of process. Perhaps the point is not what the technology allows, but the status quo around what constitutes an 'acceptable' form of identification. Whatever the solution (for personal identification) it needs to be somewhat scarce, but also ubiquitous. But different applications need different level of scarcity. Phone numbers just seem to be the right balance for social media.