First and foremost, there must be a major immediate benefit for the user. Persistent online identity - the long-elusive holy grail of "single sign-on" - offers one such, both for the consumer-oriented and the civic-minded. But how do we get mass acceptance of such a new technology among the civic-minded when it's the consumer that such services are being built for?
One path is to help the average user with managing the most valuable resource they have: their attention.