Not sure if its a good idea, Email servers get hacked daily, If you’re auto-sending payment to receiver , now there is an incentive for hackers , to spam themselves with your inbox and you pay out of your wallet for that. Now, yes one could say, that’s no problem just have a multi-wallet approval method , so unless the second one approves, it wont. But now that makes it a bit more complex, especially for newsletters…
Well in the mail you have to pay for the stamp. It's about a dollar. You could charge 10 cents...in fact, that's not a bad idea for a cryptocurrency.
A very small fraction.
4th class mail, sent to the occupant of every house, is very very cheap.
Really, the cost of adwork, logos, placement, 4 colour print is more expensive than post.