The Short and Illustrious History of Twitter #Hashtags

With Twitter having made its way to the mainstream, one early tweeting convention has brought a nerdy flavor along for the ride. It can be a bit jarring to come across Heidi Montag tweeting about her “#superficial_album,” using the pound sign to make her tweets more likely to appear in searches and become trending topics. Though we might forget where that # originated, the record shows where credit is due — and it’s to an individual Twitter user.

On August 23, 2007, the Twitter hashtag was born. Invented by Chris Messina (then with the consulting firm Citizen Agency, now an open web advocate for Google (s GOOG)), the first tweet with a hashtag read as follows: “how do you feel about using # (pound) for groups. As in #barcamp [msg]?”

Today, hashtags make tweets more meaningful and findable, traits that many users appreciate. No conference or speech is complete without a hashtag these days, binding together the ad-hoc community of observers and their pithy comments and memorable quotes. Another prominent use of hashtags is to generate memes — the sort of stuff you would see on a chain-letter quiz — for instance, #10yearsago was popular around Jan. 1 of this year, when people remembered how they welcomed Y2K, and #ff is popular every Friday, when users recommend other accounts they like to follow. Hashtags are also a prominent form of Twitter humor, offering the author the chance to contradict what they’re saying or poke fun — for instance, a friend of mine often uses the hashtag #mylifeissohard. There’s also, of course, plenty of hashtag spam, and plenty of Justin Bieber. (The site “What the Trend” is a trove for this stuff.)

According to Twitter, 11 percent of tweets now contain hashtags. This is on a platform that sees more than 50 million tweets per day. Depending on how geeky or meme-y your user base is, the hashtag count certainly goes up. Alessio Signorini, a PhD candidate at the University of Iowa, recently found 15 percent of 275 million randomly selected tweets contained hashtags. Messina said there are hashtags in probably 30 percent of the tweets from people he follows.

Back in the spring summer of 2007, Messina proposed the hashtag as a way to group conversations on Twitter, which was then an incredibly simple messaging service (of course, it still is, but a lot has changed). The inspiration for the convention came from channels on IRC and the Twitter competitor Jaiku. The # would denote metadata about a tweet, rather than the content of the tweet itself. Messina called them “channel tags.” He wrote via email today, “In the beginning people really hated them! People didn’t understand why we needed hashtags, and the biggest complaint was that people just didn’t like how they looked.”

Though hashtags might have been a little ugly and awkward, they were useful from the outset. Back then Twitter offered a push-based service called Track (since discontinued) where users could set up notifications on any term, and that worked particularly well with hashtags. What the company didn’t offer was search (it later bought Summize to fix this problem), and tracking hashtags was a sort of substitute, helping users find and organize tweets. Hashtags are also “folksonomic,” meaning they give organization that is ad hoc, with no rigid structure or approval system.

Messina's mockup of recent and popular channel tags for Twitter executives.

Messina pitched hashtags to Twitter’s execs back in the day, he said, and even mocked up a couple of pages that showed popular hashtags (still called channels) the exact same way Twitter treats trending topics today. But the Twitter team deemed them too nerdy, and said they’d prefer to use machine learning to filter tweet topics, according to Messina.

Adoption of the hashtag initially seemed to be mostly by Messina himself, who used them profusely to mark where he was tweeting from and what it was about, until around October of ’07. During the San Diego forest fires, when people tweeting about the emergency used the same hashtag at Messina’s urging and by following the example set by other citizen journalists.

Around the same time, Republicans seeking to keep Congress in session to vote on an energy bill started tweeting with the hashtag #dontgo. In Messina’s recollection, that was hashtag’s big break “out of the geekosphere.”

Messina said that in retrospect, he’s especially proud of inventing hashtags “because they’re a hack and they prove that simple solutions are often the best ways to solve a problem, rather than waiting for a technology solution.”

Ever the tinkerer, Messina now thinks hashtags are overused and that there should be different types of metadata markers, for instance /via, /cc and /by. Those have been christened “slashtags,” but they haven’t caught on quite as well.

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