Twitter users represent two different types of “content camps”
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The analysis resulted in two clusters, which we labeled “Informers” (20% of users) and – to suggest a new term – “Meformers” (80%) […] while Meformers typically post messages relating to themselves or their thoughts, Informers post messages that are informational in nature.
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Note that although the Meformers’ self focus might be characterized by some as self-indulgent, these messages may play an important role in helping users maintain relationships with strong and weak ties. Our findings suggest that the users in the “information sharing” group tend to be more conversational, posting mentions and replies to other users, and are more embedded in social interaction on Twitter, having more social contacts.
— Is it Really About Me? Message Content in Social Awareness Streams [pdf]