Ancient letters are a remarkable invention, as they contain both information (the message) and value (the stamp). In contrast, modern emails and messengers only contain information, lacking value. Service providers can't solve the spam problem and must rely on registration systems. Letters, using stamps, solved this problem more elegantly without the need for registration. nostr:note16gv0dfkfaj2cvyujxlk9thckm4vy63r9vl0hpcn9473flca9qqqscm583q