The first-ever presidential Twitter debate unfurled in rapid-fire style this afternoon, with six Republican candidates proving they can “talk 2 u” in abbreviations almost as well as a text-savvy teen.

Public participation exceeded organizers’ expectations, averaging 180 tweets per minute. When it wrapped up at 4:30, about 4,500 of the candidates’ tweets had been retweeted – that is, forwarded on by Twitter users.

But some viewers were left thinking that Twitter just didn’t lend itself to a substantive debate.

“The format leaves a lot to be desired because you can’t form a structured argument at all – they’re just sound bites,” said Bill Hannah, who came to watch the debate on a big screen at the conference center in Concord, N.H., where the event was produced. As someone who believes in many tea party objectives, he was hoping to learn where the candidates stood on his issues, but found the sometimes-disconnected stream of questions and answers disappointing.

The moderator, conservative commentator S.E. Cupp, sat perched on a high stool in front of her laptop. The live radio show of co-moderator Rusty Humphries played on a speaker, providing a bit of an echo-chamber effect as he read aloud tweets that had been posted minutes before.

After each candidate gave their opening statement in two or three 140-character tweets, Ms. Cupp tweeted the first of five questions posed to all the candidates: As president, how will you avoid continually raising the debt ceiling?

Newt Gingrich was the first to jump in, noting, “I am the only candidate who has balanced the budget.”

Michele Bachmann tweeted, “Lesson of ’82 and ’90 is promised #spending cuts never last while higher taxes persist. No more biz as usual. No debt hike.”

(By putting the # symbol in front of spending, called a hashtag in Twitter-land, she ensured that anyone searching Twitter for tweets on spending would get a look at her answer.)

Another question: Can a president create jobs without expanding the role of the federal government?

Herman Cain responded: “Lower top corp. and personal tax rates to a MAX 25%. And most importantly, make them permanent! Uncertainty kills the economy.”

Mr. Cain may be considered a long-shot candidate by political pundits, but he was popular with this crowd, which had a tea-party slant because the debate was hosted by TheTeaParty.net.

Shortly after the debate, Cain’s tweets had been retweeted more than any other candidate’s. As of 4:38 p.m., this Cain tweet was the most popular of the debate: “Government doesn’t create jobs. Businesses create jobs. Government needs to get out the way.”

On another measure of success, Michele Bachmann surged ahead, with the most @ mentions during the debate. (That means more people included her twitter handle, @MicheleBachmann, in their tweets.)

People watching the streaming comments from @140townhall – on Twitter, realtime.google.com, or 140townhall.com – could tweet in their own questions and commentary throughout the afternoon. Organizers pulled questions for each candidate.

Rick Santorum was asked, for instance, “What would be your first executive order after the disastrous Obama presidency?” He replied, “To suspend all spending on the implementation of Obamacare.”

Thaddeus McCotter and Gary Johnson also took part in the debate.

Afterwards, an “exhausted” Cupp said she was excited about how spontaneous and authentic the event had been. “I don’t think anything sounded canned,” she said. “When Cain was tweeting, it sounded like Cain, and Thad sounded like Thad!”

The debate was a bit slow to get going, as an early comment noted: “Trying to enjoy @140townhall but just don't see the benefit.”

Later tweets were more enthusiastic, congratulating the moderator and candidates on a job well done.

The Twitter debate is just another indication that “social media is the killer app for the 2012 election cycle,” says Andrew Rasiej, co-founder of the blog techPresident, which covers politics and technology. “Since political opinion is formed mostly by people talking to each other, social media has become the new highway for political discourse, voter discourse.”

But for Duke University public policy professor Kenneth Rogerson, the novelty of a Twitter debate, while fun, is “a bit of a flash in the pan.” He recalls a CNN debate that drew on questions posted via YouTube videos. It garnered excitement, but wasn’t replicated. And Twitter questions don’t have the emotional impact of videos. “You’re stuck with some pretty uninteresting questions,” he says.

Mitt Romney, who is leading the Republican field in general polls, came in for some criticism from the moderators – as did the other no-show candidates.

But it’s too early in the primary cycle, Professor Rogerson says, for debates to hold much sway with voters.

The transcript of the debate will replay for several days on 140townhall.com.