Word spreads fast on Twitter, and how does it spread best? Through the power of the ‘retweet’.

To retweet (or ‘RT’ as it is called on Twitter, due to its defining character-limit) is simply the act of repeating someone else’s post. It implies a desire to spread news, admiration for, or appreciation of the original tweet.

It’s when a single tweet gets picked up and retweeted by thousands of users that you find why Twitter is regarded by some as the holy grail of marketing: word spreads, fast, and for free.

If proof were needed that business is sitting up and taking note of the power of Twitter, look no further than an in-depth analysis from Dan Zarella. A recent blog post from Fast Company scoured his report for just nine of the qualities most likely to get you retweeted – and pointed to his 22-page work on the same.

Who would have thought a mere 144 characters could be researched so thoroughly? Read these nine pieces of advice – and, if it gets your interest, the full report – and you’ll begin to understand why.