An interesting article about how people don't understand social services/media until you try them out. This is a lot less obvious than most may think.
Take Twitter: to looks like a way for people to spread interesting things they find. The thing is, as soon as to switch to producing content (or disseminating it) you come across several issue.
What does your audience want to see, will this tweet improve existing subscriber loyalty at the cost of new subscribers. This thought process changes the person tweeting. It forces extra thought and therefore give extra insight about their audience.
So tweet even in you aren't looking for followers, if you are promoting anything specific. Tweet once a day and see how it changes how you think.