-By Brian Morrissey

NEW YORK Dell CMO Mark Jarvis had a challenge for his digital team: Come up with an innovative way to connect with consumers online and sell products -- and do it without a budget.

The team turned to the fast-growing micro-blogging platform Twitter, becoming one of the first brands to establish a presence. It started DellOutlet there in 2007 as a way to dispense product offers. Over time, it has incorporated some of the channel's more social aspects by answering questions. The team has generated more than $500,000 in revenue so far from Twitter leads.

"That's incremental, but there's zero marketing cost," said Jarvis.

Several company employees have become unofficial brand ambassadors on Twitter, trading messages with other users and sharing details both professional and personal. One employee, known by the Twitter name RichardatDell, has nearly 1,000 subscribers.

Dell is not alone among companies establishing a beachhead on Twitter, which has an estimated 1 million users. JetBlue, Comcast and H&R Block also have Twitter feeds. Comcast, under the name ComcastCares, tracks mentions of the brand and contacts people who have complaints.

Zappos CEO Tony Hsieh has amassed more than 6,000 followers, and uses the service to give away shoes, meet customers and send out mass invites to company happy hours. Thanks to his encouragement, more than 400 employees now use the service.

Some companies are trying to use Twitter to blend CRM and branding. H&R Block monitored Twitter for mentions of taxes, then offered help. H&R Block digital shop 360i spearheaded the project, but it frequently kicked questions to the clients. Sarah Hofstetter, vp of emerging media and client strategy at 360i, points out that, although setting up a Twitter account is simple, keeping it going is labor intensive.

H&R Block responded to positive or neutral mentions of the brand but mostly shied away from negative posts. The spillover: Popular blogger Robert Scoble praised the brand's efforts, an important endorsement from an online influential.

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