"These micromessages billion deal with any subject imaginable," says Twitter.
For the first half of 2011, a large portion of these messages concerned the interpretation of "Friday", Rebecca Black.
The album of Britney Spears Femme Fatale and Charlie Sheen have also contributed to the discussions of users.
More seriously, they also discussed topical issues, such as H1N1 virus, the former Egyptian President Hosni Mubarak and Libyan riots.
The Japanese earthquake and tsunami of March 11 resulted in a sending messages of sympathy and sadness.