Twitter's 140 Characters: A Critical Success Factor

Twitter is clearly a success. Millions of people are now posting and reading 140 character thoughts, questions, and updates on a regular basis.

A few weeks ago I tweeted a thought of my own:



And I'm still thinking about it.

I know Twitter limited Tweets to 140 characters based on limitations of texting. But what if that hadn't been a factor? What if they could set any limit they wanted? In a world where more is better and unlimited is best, I'd be surprised if they would set a 140 character limit.

So what if they had set the limit at 250 characters? Or 500 characters? Would Twitter adoption still have taken off as it has?

I don't think it would have had the limit been set much higher than 140 characters. There are two reasons for this:

1. Speed of Tweeting
   The short time spent writing and editing a Tweet makes the mental barrier to posting multiple Tweets per day very low. Unlike a blog post where you need to set aside a block of time to write and edit the much longer post, it's easy to write and post a tweet in a minute or less. That mental barrier is critical.
   
2. Speed of reading
   It takes very little time to read a single Tweet or even a page full of them. Tweets are easy to consume so people follow and read.
   

Think about the differences in speed of writing and reading the posts below.

140 characters:

In the beginning God created the heavens and the earth. The earth was formless and void, and darkness was over the surface of the deep, and

250 characters:

In the beginning God created the heavens and the earth. The earth was formless and void, and darkness was over the surface of the deep, and the Spirit of God was moving over the surface of the waters. Then God said, "Let there be light"; and there wa

500 characters:

In the beginning God created the heavens and the earth. The earth was formless and void, and darkness was over the surface of the deep, and the Spirit of God was moving over the surface of the waters. Then God said, "Let there be light"; and there was light. God saw that the light was good; and God separated the light from the darkness. God called the light day, and the darkness He called night And there was evening and there was morning, one day. Then God said, "Let there be an expanse in the m

Writing and reading 500 or even 250 characters takes more effort than 140. Enough effort to deter people from Tweeting as much as they do.

So what does this mean for designers? When designing a new web app you think about the standard aspects like functionality, target audience, task flows, information architecture, and look and feel. But many times we make quick and arbitrary decisions on "insignificant" aspects of the design that could actually make or break the final product.

Usually the decision on character limits would be made by a technical analyst or an engineer without much consideration for strategy or user experience. The impact of Twitter's decision to limit Tweets to 140 characters has had significant impact on its success. We need to remember that aspects of a design we often overlook as unimportant (or outside the realm of "design") can have far ranging affects on the success of the experience we're designing.