Chris Messina invented the hashtag |Twitter’s Secret Handshake

Hashtags, words or phrases preceded by the # symbol, have been popularized on Twitter as a way for users to organize and search messages. So, for instance, people tweeting about Representative Anthony D. Weiner might add the hashtag #Weinergate to their messages, and those curious about the latest developments in the scandal could simply search for #Weinergate. Or Justin Bieber fans might use #Bieber to find fellow Beliebers.

But already, hashtags have transcended the 140-characters-or-less microblogging platform, and have become a new cultural shorthand, finding their way into chat windows, e-mail and face-to-face conversations.



This year on Super Bowl Sunday, Audi broadcast a new commercial featuring a hashtag, #ProgressIs, that flashed on the screen and urged viewers to complete the “Progress Is” prompt on Twitter for the chance to win a prize. Then, in Canada’s English-language federal election debate in April, Jack Layton, the leader of the New Democratic Party, set the Canadian Twitterverse aflame when he attacked Prime Minister Stephen Harper’s crime policies, calling them “a hashtag fail.”

And when Chris Messina, a developer advocate at Google, wanted to introduce two friends over e-mail, he wrote #Introduction in the subject line. No need, he explained, for a long preamble when a quick, to-the-point hashtag would do.

Then again, Mr. Messina is no ordinary Twitter user. The self-described “hash godfather,” he officially invented the Twitter hashtag in August 2007, when he sent out a Twitter message suggesting that the pound symbol be used for organizing groups on Twitter. (For example, if attendees at the South by Southwest music and technology conference all add #sxsw to their messages, they can more easily search and sort themselves on Twitter.) Though the idea took awhile to catch on, it quickly snowballed — on Twitter and offline.

“At first, people who weren’t using Twitter were saying: ‘What’s this pound sign? Why am I seeing it?’ ” said Ginger Wilcox, a founder of the Social Media Marketing Institute. “I would say 2010 was really the year of the hashtag.”

Soon, people began using hashtags to add humor, context and interior monologues to their messages — and everyday conversation. As Susan Orlean wrote in a New Yorker blog post titled “Hash,” the symbol can be “a more sophisticated, verbal version of the dread winking emoticon that tweens use to signify that they’re joking.”

“Because you have a hashtag embedded in a short message with real language, it starts exhibiting other characteristics of natural language, which means basically that people start playing with it and manipulating it,” said Jacob Eisenstein, a postdoctoral fellow at Carnegie Mellon University in computational linguistics. “You’ll see them used as humor, as sort of meta-commentary, where you’ll write a message and maybe you don’t really believe it, and what you really think is in the hashtag.”

So, for instance, a messages that reads “3 hour delay on Amtrak #StimulusDollarsAtWork,” likely implies that the user does not, in fact, think that their stimulus dollars are hard at work.

Hashtags then began popping up outside of Twitter, in e-mails, chat windows and text messages. When Adam Sharp was hired as Twitter’s Washington liaison, he said he received a number of e-mails wishing him well — and, of course, #congrats.

In a time-crunched world, the hashtag proved itself a useful shorthand. “If Twitter is a compression of ideas and a compression of expression, then hashtags are just an extension of that, so of course it bleeds over into other forms of communication, because our time is compressed, our thoughts are compressed and our space is compressed,” said Tracy Sefl, a Democratic strategist. “In Washington, it’s a very happy extension of an acronym-happy culture.”