Smith asked about skeptics, who might think, "Who cares about somebody telling me what they ate for lunch?"
"There are always going to be people who are doing that, who are just, you know, 'Here's my dinner,'" replied Lance Ulanoff, editor-in-chief of the online social media blog Mashable.
"The moments that matter in Twitter's life span are when we were told about things that are happening in the real world. And that has sort of solidified its position as a powerful news delivery service for average people, people on the ground."
Or on the water. For example, remember the plane that bellied into the Hudson in 2009? Some of the first images were from a guy tweeting from a ferry boat.
And the first pictures of the Asiana crash in San Francisco this year were tweeted by the passengers themselves.
"Is that 'your lunch'?" asked Ulanoff. "Is that inconsequential information? No, that's sort of life-changing information."
Of course, Twitter had its own life-changing moment this past week: the company's stock price soared 73 percent in the first day of trading, but slid seven percent the next day.
From Wall Street to Twitter's headquarters on San Francisco's Market Street, all eyes are on the numbers.
And the numbers are staggering. According to Twitter, the company has more than 230 million users, who send around a half-billion tweets every 24 hours.
Last year revenue shot up 198 percent, to around $300 million.
But that brings up an equally staggering number: Twitter's net profit, so far, is zero.
The company says it'll turn that around by selling more ads, called sponsored or promoted tweets.
"Twitter makes money through ads -- as the ads pile up, does that cheapen the experience?" Smith asked Dorsey.
"I think it makes it better," he replied. "You're giving a brand or an organization an opportunity to increase the number of people who might see their content, to see their message."
"It's good for the advertiser, but what about for the person on Twitter who's reading all these ads?"
"Well, they're contextual," Dorsey said. "You know, so you see an ad, you see a promoted tweet within the stream, and it feels like it belongs there. It feels like it's part of the conversation."
And it's an open conversation, which means companies can sometimes get their message across without paying, like this Oreo tweet during last year's Super Bowl blackout -- basically a free ad.
"It explodes virally," said Ulanoff, "and Twitter doesn't really have anything to do with it."
And Oreo didn't pay for advertising.
"So that's the thing: Twitter's a completely open environment," said Ulanoff. "It's not like television, where the average user couldn't suddenly show up on TV talking about something, or some small company couldn't show up and say, 'Hey, by the way . . .' But Twitter is like that."
But as innovative as Twitter may be, the company's drawn fire for having an all-male board of directors. In the recent financial filing, general counsel Vijaya Gadde was the only female in the list of top Twitter executives.
Does that concern her? "It really doesn't," she told Smith. "That is one snapshot of who we are as a company. But it certainly does not tell the whole story.
"I'm sure that will change, I'm sure it will," said Gadde.
"Do people tweet to you directly? Do they use Twitter to say, 'Hey, why aren't there more women in Twitter?'"
"Absolutely," said Gadde. "We get a lot of feedback. And we got a lot of [interest] from] people who wanted to come here. It was an interesting dialogue. It's certainly something that we take very seriously, and is very important to us."
Another change crucial to Twitter's survival: growing the number of people who use it.
Right now, Facebook has four times as many (about 1.1 billion).
But insiders like Jack Dorsey have high expectations.
When asked where he sees the company 10 years from now, he replied, "We want to reach every single person on the planet."
"That's a lofty goal," said Smith.
"I think it has a potential to do so. It provides true utility, and it does give you a sense of what's happening in the world. So I do believe it has a potential to reach those heights."
OK, that could be overly optimistic. But maybe, by giving us a new way to talk about a rapidly-changing world, Twitter has found a permanent place in it.
WEB EXTRA VIDEO: Twitter's Jack Dorsey explains: Why 140 characters? (Click on the video player below.)
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