Among Stephen Fry’s greatest feats of understatement has to be describing himself in under 140 characters. From his Twitter bio: “British Actor, Writer, Lord of Dance, Prince of Swimwear & Blogger.” The silver-tongued cultural icon’s fan base long predates social media, but to demonstrate his incredible influence in real-time, we need only look at Twitter, where Fry has more than 1.5 million followers. His digital counsel is sought on nearly every conceivable topic, from iPhone apps to relationships, existential crises and matters of faith.

So why do we trust Stephen Fry?

He’s not a broadcaster. Twitter is a conversation platform, and Fry uses it as such. Few celebrities engage others to his extent, and those he does “ping” aren’t typically other influencers. He simply responds to tweets that interest him, and this ostensibly minor act of reciprocity makes us adore him even further. Each reply from Fry is an endorsement of sorts, increasing the recipient’s social capital in the eyes of his massive audience.

He’s one of us. Fry shares generously, and through Twitter he reveals himself to be thoroughly, approachably human. He laments. He celebrates. He gets excited. Just like we do! We are intrigued and refreshed by this; Fry seems to have found the perfect balance between sharing the public and the personal in an era where celebrities tend to gravitate to either extreme.

He uses his powers for good. Fry actively promotes charitable causes through Twitter, often yielding astonishing results. In fact, his calls-to-action are so well received; he has added a disclaimer to his site:

WARNING: When Stephen tweets a URL to a given website, up to 500,000 people will attempt to visit that website within one hour. Very few websites can manage that intense traffic. If you wish to ask Stephen to Tweet about a charity or special event which points to your/a website, it must be capable of taking 1200+ calls per second to the website’s server in order to be able to stay live once Stephen’s Tweeted.

A typical request (among hundreds per day): “@stephenfry hi im starting a #RescueCancer Movement would you mind following > @rescuecancer.”

At a time when our ability to differentiate between canned and organic messages is increasingly acute, Stephen Fry’s authenticity is central to his appeal. He has earned the trust of his community of followers by helping where he can, always engaging them as fellow human beings and refusing to be anything other than his genuine self.

Andy is Vice President International (EMEA & APAC) at Bazaarvoice.