Well, this is an interesting tidbit: Computer giant Dell told Internet News that its "Twitter sale alerts" have added up to about $1 million in revenue.
As we all know from Mike Myers' "Dr. Evil" character in the Austin Powers movie franchise, a million bucks isn't a whole lot of money for a major multinational corporation. But it does have something to say about how Twitter is transforming from gimmicky messaging tool to marketing powerhouse. Fire-sale start-up Woot showed that it's possible to take advantage of Twitter's rapid-fire nature to advertise fleeting deals; shoe retailer Zappos has gotten praise for using Twitter for customer service.
Low-cost airline JetBlue, as the Internet News article points out, also uses Twitter for both fare deals and customer service.
More compelling is what this can mean for Twitter's own not-yet-existent business model, which looks like it might involve premium accounts for businesses using the service. With companies touting retail success, this could widen the window of opportunity for Twitter to start encouraging them to, well, pay up.