The End of Spam? At What Cost?

The key to getting rid of spam probably is its economics.
On a diligently crafted Flash-only site, E Postal Exchange (there's also a HTML-only press release) explain their solution:

• Commercial emails will cost 0.1 USD per delivered piece (5 cents for the ISP, 5 for E Postal Exchange).
• Personal messages can continue to travel unhampered.

Now how do they tell which messages are personal and what is commercial? "...we won't be releasing that information." Oh, sure. E Postal Exchange also lets users set up a whitelist of allowed senders -- presumably for the personal mail that is too commercial.
And what about newsletters, fluctuating somewhere between personal and commercial? "We believe that those websites that offer these types of services can add that information to their websites for the consumer to go and look at." Thanks for the tip.