I'm not sure adding more structure is always useful. When I'm throwing a party for 30 people at a set date and time, I use event organization software, like Fa

I'm not sure adding more structure is always useful. When I'm throwing a party for 30 people at a set date and time, I use event organization software, like Facebook events. If I want to get a feeling for my friends' thoughts on the local concert schedule this fall, I want to have a conversation with them. And the subject, as in email, is meta-data about a conversation, not (necessarily) the content of the conversation.