Despite the fact that 39% of the Inc. 500 are blogging (according to a 2007 study), I've found few Inc. 5000 conference speakers or attendees who are actively engaged in using social media. And when I say "actively," I mean more than the occasional blog post.

So it was fun to meet Greg Cangialosi, CEO of Blue Sky Factory (#1,861 on this year's list), on Twitter.

Twitter, if you're not familiar with it, is the microblogging platform du jour. BusinessWeek recently profiled a handful of Twittering CEOs and featured an article explaining the brand building benefits of using this new social media tool. Twitter now has over 1 million users a month.

If you're wondering how I "met" Greg on Twitter, let me briefly explain. This may also explain why microblogging works as a marketing strategy. I tweeted about choosing a new email service provider. (Yes, "tweet" is a made-up word that explains what you do when you type a short entry, up to 140 characters, into your Twitter account.)

I mentioned @BlueSkyFactory (the company's twitter handle) as one vendor I am considering. Greg saw it and tweeted me back, saying: "Hey, let one of our sales reps give you a demo."

By checking his Twitter profile, I quickly determined that he was CEO of the company. I was impressed. A CEO who would take the time to contact me directly?

I chatted with Greg by phone today to find out why he's spending time, as a CEO, on Twitter.

"I'm one of the converted CEOs that gets it," he told me. "And my sales force does too." He's convinced that business development is a by-product of participating in conversations. "All these tools (the company also has a blog and a Facebook page) are ways for us to amplify our signal."

Even more effective, he explained, is when a third party recommends your company via Twitter or in the blogosphere. When social media guru Chris Brogan mentions Blue Sky Factory, "we get a flood of inquiries," Greg said. Chris has nearly 15,000 followers - people who have signed up to follow or read his every tweet. (Anything over 1,000 followers is considered an impressive following.)

Oh and if you've read this far, visit my Twitter profile, sign up for a free account and then "follow" me. That way I'll see your messages when you tweet. Put the @ sign in front of my Twitter handle (like this: @debbieweil) and I'll see what you're writing.

I'll be twittering updates from the Inc. 5000 conference floor the rest of this week. I'm looking for more examples of Inc. 5000 companies who are using social media as a marketing strategy - and finding it effective. Come find me if you're one of them.

Full conference agenda here.