If You're Going To Be A Famous Billionaire, Strive To Be As Cool As Elon Musk

Elon Musk is the founder of three companies: Tesla, SpaceX and SolarCity.

He's a billionaire but he still makes himself approachable. In fact, the soft-spoken CEO told Business Insider's Henry Blodget that his "core competency is responding to emails."

Last week, Musk spoke at Business Insider's annual Ignition conference. The conference draws a lot of star power in its speaker line-up, from TV personality Dr. Oz to billionaire Mavericks owner Mark Cuban to Russell Simmons.

Musk arrived alone. No PR person. No employees. No posse. Just himself. (For comparison, another speaker arrived with about ten other people.) He also arrived a few minutes early and happily chatted with Business Insider's giddy editors.

Elon Musk was the closing keynote the second day of the conference. As his hour-long interview rapped up, the audience began to line up, blocking him from getting off the stage.

A lot of people would have been frustrated and bolted, or answered one question then dashed. But Musk let the crowd surround him. He stayed an extra 45 minutes to answer their questions. He even graciously accepted a piece of fan mail written by one attendee's son.

Here's how big a crowd Musk can draw. Thousands of people filled all chair, floor and standing space at Dublin's 10,000-person Web Summit just to hear Musk speak a few weeks ago:

Here's a photo of Musk staying for almost an entire hour to answer questions after Ignition.