One of the problems we have when thinking about the new real-time media streams, like Twitter and Facebook, is that our metaphors are usually based on old media forms (e.g. television or radio, or even, in some descriptions a cocktail party). For example, thinking about Twitter as television means that there is a tendency to think in terms of channels, programming, a passive audience and interactivity limited to selecting the channel to watch. It is no surprise that YouTube borrowed this ‘comfortable’ metaphor to explain to users what it was. These metaphors can therefore stifle how we understand a new media platform, and perhaps even shape the way it is further used. Here, I want to argue that if we are to understand the medium of Twitter, then we should try to look at the properties that are particular to it as it currently stands:
- It is a real-time medium.
- Information flows through it, if you miss it then the information passes by (although look at Google’s response in the creation of Google Replay).
- It is based around an interest graph (things people find interesting rather than friends or colleagues) (Barnett 2010).
- It is very flexible, even with the 140 character restriction the content of a tweet is textual and can, due to being able to support urls, point to any other form of media (e.g web/photos/video).
- The entire tweet (as a JSON data entity) can carry location data, user data and other contextual data that makes it extremely powerful.
- It has little memory, right now you can only retrieve the most recent 3,200 tweets per person (Haines 2011). However, Twitter does pass over its entire archive of public Tweets to the Library of Congress for storage and research after six months for internal library use, for non-commercial research, public display by the library itself, and preservation (Twitter 2010).
- Twitter has a client/server structure. Should Twitter go down, then so does the ability to share on the network.
The stock ticker was invented in 1867 by Edward A. Calahan, an engineer associated with the American Telegraph Company. It was a printing telegraph with two independent type-wheels, placed under a glass bell jar (to keep off dust) and powered by a battery (Jenkins et al., 1989: 153). The wheels were mounted face-to-face on two shafts and revolved under the action of an electromagnet. The first wheel had the letters of the alphabet on it; the second wheel had figures, fractions and some letters. The inked wheels printed on a paper tape divided into two strips: the security’s name was printed on the upper strip and the price quote on the lower one, beneath the name (Preda 2005: 755).
The 140-character limit of Twitter posts was guided by the 160-character limit established by the developers of SMS. However, there is nothing new about new technology imposing restrictions on articulation. During the late 19th-century telegraphy boom, some carriers charged extra for words longer than 15 characters and for messages longer than 10 words. Thus, the cheapest telegram was often limited to 150 characters (Schott 2009).
With the growth of stock exchanges, the stock ticker companies developed a client/server structure with price changes being transmitted back to the centre, which were then resent out to the provincial exchanges. For the users of the ticker service, unlike the telegraph, the stock ticker printed its message out as a continual unfolding stream of information on paper which could be read by anyone:
The flow of price variations visualized the results of ongoing conversational exchanges, and disassociated their results from the individual authority of the participants in those conversations. At the same time, the flow linked the results to each other, made the ties that bound them visible as the tape unfolded, and made the market in its turn visible as an abstract, faceless, yet very lively whole. All the felicity conditions that made the speech act valid (intonation, attitude, look, wording, pitch of voice, and so on) were blanked out. Authority and credibility was transferred from the broker’s person to the machine. The flow of figures and letters on the ticker tape became an appresentation (Husserl 1977 : 112, 124–25)… In other words, perception (of price rhythms) and representation (of floor transactions) fused together (Preda 2005: 763).
In his reminiscences, Richard D. Wyckoff (1934a: 37), a stock operator and pioneer of chart analysis, wrote that in 1905 friends of his could sit and watch the tape for an hour and a half without any interruption. Wyckoff himself had trained hard so that he could watch the ticker tape for up to an hour. He remembered how in 1907 James R. Keene, the financial speculator, fell into a ‘ticker trance’:
I used to stand facing him, my left elbow on his ticker while talking to him. He would hold the tape in his left hand and his eye-glasses in his right as he listened to me, then on went the glasses astride his nose as he bent close to the tape in a scrutiny of the length that had passed meanwhile. I might be talking at the moment his eye began to pick up the tape again, but until he finished he was a person in a trance. If, reading the tape, he observed something that stimulated his mental machinery, I might go on talking indefinitely; he wouldn’t get a word of it …. He appeared to absorb a certain length of tape, and to devote to its analysis a specified interval, measured by paces. Sometimes he returned to the ribbon for another examination, followed by more pacing. (Wyckoff, 1930: 148, quoted in Preda 2005: 766)
The stress on observation and attentiveness fitted in very well with the overall discourse of the ‘science of financial markets’, so popular in late 19th century. It required of investors precisely those qualities preached by manuals: attention, vigilance and constant observation of financial transactions and of price variations. For the investor, it is only reasonable to follow the market movements and to try to be efficient (Preda 2005: 773).
a ragged temporal structure was replaced by a smooth one, with the consequence that price variations became visualizations of market transactions and objects of symbolic interpretation. The ticker made market exchanges visible as they happened, disentangled them from local conversations, and transformed them into something that is both abstract and visible in several forms to everybody at once. They are visible in the flow of names and prices on the paper strip, but also in the financial charts, which are nowadays also produced in real time. The quality of price data changed: instead of multiple, discontinuous, heterogeneous and unsystematically recorded prices, we now have single, continuous, homogeneous, nearly real-time price variations (Preda 2005: 776).
 ‘Agencement is a common French word with the senses of either “arrangement,” “fitting” or “fixing” and is used in French in as many contexts as those words are used in English: one would speak of the arrangement of parts of a body or machine; one might talk of fixing (fitting or affixing) two or more parts together; and one might use the term for both the act of fixing and the arrangement itself, as in the fixtures and fittings of a building or shop, or the parts of a machine.’ (Phillips 2006).
 ‘It should be noted here that in the USA and in Britain, at the time of the ticker’s invention, several efforts were under way to develop machines for making speech visible. On the one hand, there were attempts at developing technical devices for the deaf, connected to the method of lip-reading. The people involved in these attempts were also involved in the development of better telegraphic devices and tried their hand (though unsuccessfully) at a telegraphic machine fitted for financial transactions. Alexander Graham Bell’s father was among those making such efforts’ (Preda 2005: 777, fn 8). It would be interesting to have a Twitter to speech ‘radio’ with an automated text to speech system (see VoiceForge).
 It is also an interesting observation that in a similar way in which stock tickers, data feeds and financial markets are visualised, there are also many competing Twitter visualisation systems, including Visibletweets.com, tweepskey.com, Twitter StreamGraphs, isparade.jp, toriseye.quodis.com, revisit, twistori, MentionMap.
Barnett, E. (2010) Twitter building ‘interest graph’ to target users, The Telegraph, accessed 13/02/2011 http://www.telegraph.co.uk/technology/twitter/8016062/Twitter-building-interest-graph-to-target-users.html
Hubspot (2009) State of the Twittersphere, June 2009, accessed 13/02/2011 http://blog.hubspot.com/Portals/249/sotwitter09.pdf
NoLOC (2011) #NoLOC.org: Keep Your Tweets From Being Archived Forever, accessed 13/02/2011 http://noloc.org/
Phillips, J. (2006) Deleuze and Guattari, accessed 13/02/2011 http://courses.nus.edu.sg/course/elljwp/deleuzeandguattari.htm
Preda, A. (2005) Socio-Technical Agency in Financial Markets: The Case of the Stock Ticker, Social Studies of Science, October 2006 vol. 36 no. 5 753-782.
Raymond, M. (2010) How Tweet It Is!: Library Acquires Entire Twitter Archive, accessed 13/02/2011 http://blogs.loc.gov/loc/2010/04/how-tweet-it-is-library-acquires-entire-twitter-archive/
Schott, B. (2009) Twittergraphy, The New York Times, accessed 13/02/2011 http://www.nytimes.com/2009/08/03/opinion/03schott.html?_r=1