Twitter is a superb medium for getting a message out.

And it’s RT (ReTweet) convention means that tweets can go viral very quickly. However, if you want to be ReTweeted, you need to make it easy or people won’t do it.

What do I mean?

Well, if you have a tendency to fill up your 140 character allowance in your tweets, the chances are that you won’t be ReTweeted much – why? Because people wanting to ReTweet you will have to do work (edit the post) to get it to fit within their own 140 character limit! Reduce that workload by ensuring that your Tweet will fit within their 140 characters effortlessly and you will be ReTweeted more often.

Hence the Twitter “Magic Number”. What is the Twitter “Magic Number”? It is the number of unused characters you need to leave at the end of your tweet so people don’t have to edit your post if they want to ReTweet it.

My Twitter ‘magic number’ is 16 – I always try to write my tweets leaving at least 16 characters free at the end. this allows people to do a “RT @tomraftery: ” – so they can easily RT my tweets without having to edit the content to get it to fit in 140. Of course, leaving more than 16 spaces at the end of my tweets allows people to add a comment or bit of context to their RT which is even better.

How do you calculate your Twitter ‘Magic Number”? It is the number of characters in your username (11 for @tomraftery) + 5 (for the RT, the : and the requisite spaces).

Now might be a good time to take another look at your Twitter username and see if you can find a shorter one that works – obviously the smaller your ‘Magic Number’ the more you can fit in your own Tweet, while still facilitating easy RT’ing!