From Hubspot on 17 August:
Last week, Laura "@Pistachio" Fitton presented a fantastic webinar for Inbound Marketing University about the business benefits of Twitter. (Laura is a famous Twitter Queen, founder of the first Twitter for Business consultancy, co-author of Twitter for Dummies, and creator of a new Twitter applications startup.) You can watch her IMU webinar here.
One of the major questions that she addressed in her presentation was, "If my best leads and potential customers aren't on Twitter, why on earth should I be on Twitter?"
Laura has concisely determined five "off-platform benefits" of Twitter, even if you aren't using it to communicate with leads and customers directly.