1) yes there are people listening on twitter.
2) they organize themselves into communities.
3) If you are interested in a community it is possible to participate in the community and get responses from interesting people.<p>If you are trying to tweet people who don't reply, Twitter seems like talking into a black hole.<p>If you do not belong to a community, you don't find tweets from actual people (who reply to tweets).<p>If you are not interested in any community, you won't find a peer group to communicate with.<p>What i'd be interested in building (or seeing someone build) is a service that indicates the % likelihood that a particular person will respond to @messages to them.