Here's a little secret about TED Talks that you wouldn't know from the carefully-selected glossy online videos that have racked up 6.1 billion views online.
In person, it does not always go well.
I'm not just talking about the occasional stumble, though I did see that covering last year's TED Talks: more than one speaker, brow dripping with sweat, had a deer-in-headlights moment from a forgotten line or emergent stutter.
That, the audience will forgive. Silicon Valley CEOs and Hollywood A-listers applauded, rallying the speaker to keep going.
But what's likely to lose them, the head of TED reveals as the annual conference returns to Vancouver this week, is mimicking a style that has gone viral.
"Be very careful of that approach," Chris Anderson warned in an interview.
"Because if what you do seems familiar or copied, it's probably going to bomb."
'The cliché of TED'
Anderson is aware of how prone to parody the TED Talk format has become since the first talks went online in 2006.
"The joke is that Kelly's character is an empty vessel with nothing to say and an impressive, reassuring way of saying it," wrote the AV Club's Joe Blevins.
Anderson takes on this problem in his recent book, TED Talks: The Official TED Guide to Public Speaking, recalling a speaker who loved his time on stage a bit too much — pausing for laughter, claiming to offer an important truth, but delivering nothing.
"I felt sick to my stomach," writes Anderson of the talk, which was never posted. "This was the cliché of TED that we'd tried so hard to eliminate."
"People had felt manipulated. And they were."
Avoiding the 'uncanny valley'
What makes a hit will depend on the speaker, but Anderson does have one other hard-and-fast rule: prepare.
Jill Bolte Taylor, the neuroscientist whose talk about experiencing a massive stroke has racked up 20 million views, practised "literally hundreds of hours" for the 18-minute performance, she recounts in Anderson's book.
"Even in my sleep ... I would awake and find myself reciting the talk."
Speakers aren't required to memorize their talk word-for-word — some use notes, and others, like Bono, have used prompters.
Instead, Anderson tells presenters to go far enough in their preparations to cross the "uncanny valley," a concept borrowed from computer animation where near-human renderings are likely to look creepy.
It's similar for public speaking, writes Anderson, where a memorized script that's just recited, but not spoken with meaning, will have neither the freshness of improvisation or the polish of true practice.
TED gets political, sort of
This year's sold-out conference, which is held April 24 to 28 at the Vancouver Convention Centre, will focus on artificial intelligence, the future of work, and how to carry on civil discourse in an era of deep political divides.
For the first time, according to Anderson, this year's line-up will include talks that directly reference "the political situation," referring to the surprise results of the U.S. presidential election and Brexit vote.
However, Anderson is quick to point out that doesn't mean partisan. (TED is owned by a non-profit foundation, which gives it certain tax exemptions but also puts restrictions on political activities.)
"TED is certainly non-partisan, and we seek to hold true to that," he said.
"What we can't escape is that people's minds are on questions that have been provoked by political situations."
Top talks at last year's conference
This year's program also teases a surprise "world figure," who has not been named but will take the stage after tennis champ Serena Williams Tuesday night.
But celebrity is not required for a successful talk.
The list of top-viewed videos from last year's TED, also held in Vancouver, isn't led by the event's best-known speakers.
And for topics, they're not newsworthy, but the stuff of life: procrastination, lying, bravery, and identity.