Tinman Michael Dell has been making a killing using social notworking sites like Twitter. Dell said that social networking site promotions have helped generate more than $6.5 million in orders for PCs, accessories and software.

The number of users signing up to get Dell's tweets has risen 23 per cent in the past three months and now numbers 1.5 million. Manish Mehta, vice president of Dell's online unit has a team of a 100 employees send out the tweets over 35 different channels.

Two years ago Dell was one of the first to start using Twitter to reach new customers. While those sales are a fraction of Dell's $61.1 billion in annual revenue last year, the company sees Twitter as one of its most significant ways of interacting with customers. Mehta said that it was all a vibrant channel for Dell and it's growing aggressively.

Dell reaches Twitter users in 12 countries, including the US, Brazil, Mexico, China and Japan. Dell reaches 3.5 million people across the web through social networks and its own community sites, including Direct2Dell.com and IdeaStorm, Mehta said.