The numbers you list in your argument against a micropayment system being able to function are a fraction of the number of transactions Facebook deals with in updating newsfeeds for the billion+ users on their system.[0]
... which is completely irrelevant because they don't have a double spending problem. Sheesh. It's easy to scale up stuff that is trivially parallelizable.*
Also, I wrote that ten years ago. Add an extra zero or two to the numbers if you want, but it doesn't make any difference.
Regards, John Levine, [email protected], Primary Perpetrator of "The Internet for Dummies", Please consider the environment before reading this e-mail. http://jl.ly * - a term of art, look it up

