Barence writes "Dell has admitted to raking in over $3 million from advertising its products on Twitter. The PC maker has been using Twitter for two years, and employs proprietary software to track sales from users clicking through from Twitter links. Of that $3 million, the company claims that $1 million was made in the past six months, following an explosion in Twitter's popularity. (Here is an analysis indicating that 72.5% of Twitter users joined in 2009.) The majority of sales have come through the @DellOutlet account, which posts six to ten special offers a week — with at least half of these being Twitter exclusives. Though the $3 million is a drop in the bucket given Dell's $12.3 billion in revenue during the first quarter of this year, it further bolsters Twitter's case for charging businesses."