Is there a way to put content behind a paywall on nostr? I'm no fan of paywalls, but specifiable rates could entice more businesses and artists to use nostr. Imagine putting a hashtag on some notes that specify that it can only move across a relay if a payment is made - that would allow artists to post like normal but also put their paid content in followers' feeds, while not bothering people who follow but don't subscribe. I remember how Twitter was really pushed by businesses on their old platforms before most casual twitter people started using it. Same effect could happen here. But if Twitter becomes a blue wechat first, the opportunity will be missed.