FORTUNE -- Depending on where you go online and what you read, much of what you see about Twitter might be negative. "Who cares what some lonely guy had for lunch?" is one variation on a common refrain.
But Twitter, unlike many other forms of media including other social sites, is what you make it. Taken as a whole, Twitter is silly and inane because most of what goes on there is silly and inane. (Just watch the trending topics.) But if you're a serious professional who uses Twitter mostly for work, you may not have to see very much of the silly and inane stuff at all. Twitter is a gigantic set of highly segregated neighborhoods, albeit ones with extremely permeable borders. If you're in the audio-equipment business, for example, you can follow and be followed by only people in that business should you choose to. Compared to some random pre-teen's Bieber-centric Twitter experience, it's a whole different world.
A set of stats recently released by the British creative shop Touch Agency helps make the business case for Twitter. For instance: 88 of the companies on the Fortune Global 100 list update their Twitter accounts at least daily. And: Three-quarters of people who follow brands on Twitter are more likely to buy from that brand.
Other, more-general stats might surprise. Some 70% of Twitter users are outside the United States. And, every second of every day, more than five new Twitter accounts are created, amounting to about 450,000 new accounts daily. One caveat: these numbers likely vary somewhat in reliability, collected as they were from as Touch puts it, "a range of online sources." Still, an interesting case for Twitter nonetheless.