For a lesson in why blogging and other forms of social media are relevant, look no further than this week’s Macworld Expo in San Francisco. Around this time every year, Apple hosts this event to showcase its latest technology. Other tech companies do the same thing, of course, but only Apple has managed to raise the conference to high art, with fans of the company speculating for months beforehand what CEO Steve Jobs will announce. In the weeks leading up to the event, Appleheads work themselves into a near-frenzy, filling the blogosphere with chatter.

Apple has found a way to leverage the power of crowds, to focus today’s tools of social media to raise the volume on its message to a degree greater than anything it could ever buy from an advertising agency. Apple doesn’t actually write its own blogs - we’ll talk about the benefits of that in another bog entry - but you can bet your next mortgage payment that its employees are actively patrolling Facebook, MySpace and blogs large and small.

They do this to better understand what’s driving their market and assess what their competitors are up to. Reading what the average consumer has to say about current products helps inform and guide the stuff that’s in the pipeline. Companies that fail to incorporate social media into their market research efforts lose a valuable source of information, and are at greater risk of losing touch with the customers that keep them alive.

So Steve Jobs doesn’t write a blog. But he’s reading them along with most of his employees, using what he learns along the way to build products that people will line up for days to buy. Blogging is as much about the reading as it is about the writing. What will your readers learn about you the next time they load up your blog?

We’ve touched on the What and the Who. It’s time for the Why.

Recognize, however, that we can talk about the big Ws forever. At some point, it makes more sense to simply dive into the blogging pool. End tangent.

Knowing why you’re writing is critically important. It explains why people will visit you regularly and what they hope to get out of the process. It articulates, in concrete terms, the value proposition of your message. If you don’t know why you want to write a blog, chances are your readers won’t, either.

We’ve asked you to ask yourself a lot of questions in previous entries. These still apply, so feel free to review them anytime. Now it’s time to put it all on the line and ask yourself why anyone would invest time to read - and respond to - anything you’d write or share. What will they get out of doing so? Why is your message any better than anyone else’s?

If you can’t answer these questions, think it over a bit before proceeding. If you’re ready to start brainstorming responses, your blogging future awaits.