A News.com article provides further details on Bill Me Later, an alternative online payment service previously mentioned by "Scott" in conjunction with my Market-based Credit Card idea.

I finally get it.  Psychologically, deferred payment is a great gimick, almost as great as xx% off sale.

Two concerns raised by the News.com article were the potentially large cost and difficulty of managing authentication and transaction liability.  One possible way to address both concerns is to offer aggregated billing service with an eye toward lowering cost of billing for companies that have existing trust relationships with customers.

For example, I have been paying PG&E, my gas and electricity company, for ages.  Politics aside, there is no reason for PG&E not to use Bill Me Later to collect payment if the cost of billing is lower.  The key point here is that my PG&E acccount can be used as a basis of trust for my Bill Me Later account.  Compared to using an e-mail address as the primary basis of trust, which is what Passport does, my PG&E account is more trustworthy.