
Traffic on Twitter has exploded. Businesses such as H&R Block (HRB) and Zappos are now using Twitter to respond to customers. Market researchers get minute-by-minute trends. Media groups use Twitterers as first-to-the-scene reporters. (They were on top of the May 12 China earthquake within minutes.)
http://www.businessweek.com/print/technology/content/may2008/tc20080514_269697.htm