Earlier quoted context omitted.
Do the outbound rules of other participants include microtransactions? And who besides a spammer would pay more than $0 to have their message read by you? If I wrote a blog post about vulnerabilities of blockchains, or how I ran Doom on a pregnancy test, and you don't read it because I'm not paying you, you're losing value, not me. You guarantee an inbox of only spam — but at least you get paid for it.
If you've got great content, I would just follow you. Or someone I follow would follow you, and through the network it would lead to discovery. I want your content, so unless you charge for it, nobody's paying anyone. If someone wants me to ingest something novel from far outside my network, one way to gain reputation might be to pay a microtransaction fee. I'd be free to choose to set that up as a part of my ingesti…
Nice in theory. In practice spammers will plant malware to steal microtransaction money from random people and push paid content down your throat for almost nothing. When you propose a novel model that will fix all the current problems, the first thing you need to think is how a bad actor would exploit it.