Smart companies like JetBlue and Zappos are legitimately engaging on Twitter, says Steve Rubel. It’s becoming a front line for customer service. At a minimum, every consumer facing company should be monitoring the chatter. Even better, participating can cut problems off at the pass or even better foster evangelists.

New figures from Hitwise show that year on year, Internet visits to Twitter.com are up 8 fold. In the past three months, visits have more than doubled and traffic continues to climb, up 60% in the past month.

The site ranked #439 among Social Networks and Forums last week and #4309 among All Categories of websites. Are you listening?