SMS, IM or Twitter? Why Not All of Them?

By Tsahi Levent-Levi

Categories: Technology

October 24th, 2008

SMS is king today. At least in the realm of text communications on mobile handsets. I have seen people praise IM as the savior of SMS costs, and others who saw the death of blogs in Twitter’s micro-blogging service. Not going to happen.

I’d like to suggest a different way of looking at it: as a set of different services that give different added value for users. And for that, I’ll start by specifying what a service is.

How do we define a service?

Any kind of network based communication service between people can be defined by a set of 4 parameters: bandwidth, immediacy, direction and participation.

• Bandwidth – from low to high. You start from text based communication, to images, to voice, to video, high definition and then end at TelePresence today (until we start doing 3D).
• Immediacy – services are either synchronous, where you expect to get a response or a feedback immediately; or asynchronous, where feedback is either unexpected or can be delayed.
• Direction – services are either unidirectional in nature (you get a feed of data but can’t respond to it) or bidirectional, where both sides of the “conversation” participate.
• Participation – how many people on each “side” of the service exist. From 1:1 services, to 1:N and to M:N.

There are grey areas as well – a service can accommodate for several aspects of a given parameter. It can be a unidirectional service at one time and become bidirectional in another case. But in essence, the nature of a service can fit a specific set of these parameters.

So where are SMS, IM and Twitter located?

I can take this model and play with VoIP related services, but let’s get back to our 3 mobile text services.

They are both on the low scale of the bandwidth parameter as they are textual in their nature (I know – you can send images and files over IM, but it is a text-based service in its core).

They differ in the other 3 parameters:

While an SMS service allows sending a short text message to another user, it doesn’t guarantee that the message is sent and received immediately; and there’s no social obligation to answer an incoming message.

An IM service, on the other hand, is more synchronous in nature – you expect people you send a message to answer you in a relatively short span of time, and you view the message as part of a chat, making it bidirectional in nature.

Twitter is closer to SMS as a service, and can easily be seen as a cross between blogging and SMS. You send out a message to a set of followers (hence single direction) and you don’t really expect them to view it the moment you send it.

These services are different in nature even when they can be used for the same task. You can hold a chat over IM or over SMS, but doing that over SMS will be clunky at best.

None of the three is going to vanish – they are used differently. This simply means that SMS is here to stay. If you think that the high cost will kill it then you are wrong. Once operators see their profits from SMS drop, they will surely drop its cost as well.