We've been here before, but to recap.
1. If a particular billing/business model presents difficulties then we might have to consider a different model, others are possible (hence, straw man of e-postage etc.)
I look forward to hearing about a design for an email billing system that does not require technology that is two orders of magnitude beyond the state of the art and would be effective against spammers. I hope my inability to envision one is just due to lack of imagination, but I've been asking for years and I've never seen anything even close. It's not hard to sketch out a scheme that does statistical billing and works so long as everyone plays more or less by the rules. It is far harder to come up with one that will work against determined bad guys who would be delighted if 1% of their mail leaked through without paying (or paid by other people.)
2. It would seem to say, for example, the long distance voice billing system is impossible since it would seem to have many of the same qualities you delineate as insurmountable obstacles.
Telephony is heavily regulated, has high costs of entry, has nothing comparable to the spam problem (fraudulent callers at higher volumes than legit callers), and is still subject to gross frauds like MCI. I'm thinking both of MCI's accounting frauds, and of more technical stuff like routing calls through Canada and reoriginating them at small telcos in the upper midwest to make them look like local rather than long distance traffic. Is that really the business you want to be in? It is also my impression that the number of phone calls is a whole lot less than the number of e-mail messages, returning us to the previous problem. I can't help but note that telephony is rapidly moving in the other direction, away from itemized billing. My phone service is now flat rate for calls to anywhere from Honolulu to Helsinki. Perhaps they know something.
Most importantly the big difference between those billing systems and e-mail is that there are billions and billions of dollars in those voice billing systems and the systems they support. There is very little money in e-mail,
This part, I completely agree with. No matter what anti-spam technique you propose, someone will complain that it costs too much. (This is particularly true of bulk marketers who apparently think that if e-mail were merely 100 times cheaper than paper mail rather than 1000 times cheaper, mass bankruptcies would ensue.) Spamhaus says, on the record, that MCI and SBC will not disconnect spammers for anything other than non-payment. The money is talking there. One of the few hopeful signs on the horizon is that Verizon, for all its faults, has a lot better history of booting off spammers than MCI does. R's, John