What’s your number? It’s not 867-5309 ….

I got into an interesting discussion with a student recently as I was training him to work on a Twitter project we have cookin’ here at Lehigh.

I was explaining the concept of “retweeting” on Twitter and why it was such a valuable thing. For those who don’t use Twitter a lot, the idea is that your audience is opt-in (if they’re not clicking the button to “follow” you, they don’t see your tweets unless they bookmark your profile page). Thus any tweet really only reaches the people following you (oh, and also the millions of social media “experts” who troll the live public feed). A retweet, which has one of your followers copying and pasting your message and sending it out to their audience, is valuable because it allows other users who aren’t following you to discover you through social connections.

We call this process of discovery “serendipity,” a concept we use for other media to describe running into information that we don’t expect. Someone on Twitter (I forget whom, but I know it wasn’t me) once put it another way: Your tweets last about an hour before they are pushed down in someone’s Twitter feed, but a retweet extends its life another 5-6 hours just because of serendipity on other non-followers’ feeds.

Anyhow, I was explaining to the student why a short Twitter username really helps. My handle is “jlittau” and so any retweet has to start with “RT @username ” before any pasting of the actual message. The “RT,” space, and “@” before the username is four characters right there. So if your tweet that inspires someone else to retweet is 140 characters, that means they automatically have to take out 5 characters plus your username off the top to make it fit because the retweeter only has 140 characters too. Thus, a shorter name is kinder to both your message (easier to keep it intact) and the retweeter (who probably doesn’t want to edit). [edit note: added the extra space after the username and throughout thanks to a helpful comment from Bob Britten. I didn't get into this for the math.]

Now, some of you rightly don’t care if you’re retweeted. You’re posting and don’t care about followers or having a message go viral across a few networks. You’re in this for the personal satisfaction of Telling The Internet Things.

But most of us, we are narcissists. We have to be – we are on Twitter, after all. I can tell you that when most folks retweet me, I am lucky to gain a new follower. But two people in particular, Markos Moulitsas (@markos) and Jen Reeves (@jenleereeves), tend to grow my network when they retweet my messages. Why? Probably because they have more than 13,500 followers combined to my 280something. Getting retweeted by folks like Markos can be a lot of fun if you like seeing how far your messages can go.

So in talking with the student (@VoterVictory), I was making a case for short usernames, and the student brought up an interesting point. It’s really not the length of your handle so much as the length of your tweet relative to that handle. For the sake of coming up with new terms that nobody will ever use, I’m calling it “Your Number.”

So here it goes. You have 140 characters. Your “Retweet Cost” is “RT @username ” (with username being whatever name of whatever length you choose, plus a space afterward) if you want someone to be able to retweet you without any editing. So, for example, my username has 7 characters plus the five for the “RT @” and an extra space afterward …. this means my Retweet Cost is 12 characters. Your Number, then, is 140 minus your Retweet Cost, which in my case equals 128 characters. As long as I keep my tweets at 128, people can retweet me without editing.

If you want to get really hardcore and allow for people to add a little commentary, subtract 20 characters. This means my Number is 108.

In other words, 140 characters is so the-first-10-months-of-2009.

Why is this important? Because some of us (me) are lazy. I don’t mind editing a few characters, but if we’re talking anything over 12 then I start to really evaluate how valuable it is to pass this tweet along. And I also have a crazy ethical thing about editing without transparency, so I always use “eRT” if I chop anything out … another lost character to deal with.

Will some retweet? Sure. But look at it as a Godwin’s Law type of thing: The more characters that must be cut to retweet, the more your odds of not being retweeted approach 1.

Still, don’t be tempted to think this means you can have a long username if you stay within Your Number. I used to say use short usernames to make retweeting easier. But even if you keep it to Your Number, it affects you by having a long name. The longer your name, the more it costs you the ability to be more clear or poignant. Narcissism still matters.

I saw this at work a month ago when Matthew Berry (@MatthewBerryTMR) at ESPN changed his name. His username before was “TheRealTMR” (10 characters) but he changed it to “MatthewBerryTMR” (15 characters) to “better” brand himself). I sent him a reply message saying that was a bad idea for the aforementioned reasons (you lose chances at serendipity by making it harder to retweet). In addition, his bio brands himself easily. If someone’s searching for Matthew Berry on Twitter via Google, his name in the bio is all he needs.

His response was “it’s just a few more characters.” He clearly doesn’t get Twitter if he expects the audience to adapt to him; there really is a system that rewards reciprocity in social media, and part of this whole thing is thinking about and listening to your audience. Berry had a lot of folks telling him why he was wrong, and it’s too bad he wasn’t listening.

The flipside is that even if Berry sticks to the Your Number concept and keeps his posts to 120 characters (which he doesn’t) to make it retweet-friendly, he’s costing himself space. Anything over the Your Number concept and he’s not thinking about his audience. Needlessly increasing his Retweet Cost by having a long username, and he’s not thinking about his own content.

So now I know my Number (128). The bad thing is I tend to use a lot of Twooshes (use of the full 140 characters) and I have to get in the habit of thinking 128, not 140. But the little things tend to matter on platforms like Twitter, where the power of being discovered can really open up the gates to your message being widely received.

From here on out I will still teach short usernames, but it has to go with a message about Your Number. They both matter, for different reasons.