Nobody's quite sure about Twitter's usage statistics; the microblogging service doesn't release them and they're loathe to comment on usage speculation. One thing we're certain of, though, is that Twitter users number in the millions, and that massive and steadily-growing user base has given Twitter the ability to take niche topics and bring them out into the mainstream.

Shedding light on niche topics has been one of the greatest things about the internet in general since its conception, but Twitter takes the process of bringing out niche topics and supercharges it. Practically any topic you can think of can be and is actively discussed on Twitter, as you can readily discover using Twitter's search engine.

What is it about Twitter that makes seemingly random, under-appreciated topics gain mainstream popularity and exposure? It's all about the shortness.

The problem with niche topics is that, although many people may be dimly aware of them, there are typically few experts, and those experts are typically not geographically centralized. Although you may be fascinated about mercury levels in groundwater, that doesn't mean that your friends are going to be interested enough in the topic to learn enough about it to carry on a conversation with you about it.

Enter Twitter. Using Twitter's powerful real-time search capabilities, you can instantly find people who are talking about exactly what you're interested in, whether they're living right down the street or across the globe - and unlike the internet, where you can find a wealth of forums and bulletin boards addressing practically every topic known to man, on Twitter, you can find them quickly, and you can find people who are discussing those topics right now.

The overall effect of the smorgasbord of topics discussed on Twitter is that you get a typical bell-curve distribution, with the majority of Twitter users talking about a minority of "mainstream" topics at any given moment. What you also get, however, is that "long tail" of topics, whose number is far greater, who are being discussed by a minority of Twitter users. The thing is, as Twitter's user base gets larger and larger, that "minority" of Twitter users also grows larger and larger - effectively increasing the number of people discussing those "long tail" niche topics to greater levels than you've ever been able to gain access to before.

Twitter's goal is to gain tens, maybe even hundreds of millions of users. Internal documents suggest that they have toyed with the notion of what Twitter would be like with a billion users. One thing is for certain: as long as people continue to join Twitter and use it in the way that they're using it now, we're going to see more and more niche topics addressed on the microblogging platform, providing a little of something for everyone. So go ahead and tweet about the most random, obscure topics known to mankind - if you do a little Oct 12, 2009