Twitter might allot us 140 characters to express a thought, but what is the "just right" length for a post? FastCompany's Kevan Lee compiled a small mountain of research on social media engagement and found the ideal length for posts on a number of platforms, and the middle ground is where it's at.
For Twitter, that clocks in at around 100 characters; a length that gives you time enough to say your piece and include an abbreviated link. It also leaves room for followers to retweet and add commentary. (It's worth noting, however, that Lee points to research done primarily on brands, not individual users.)
Facebook is a bit trickier. Lee highlights a couple of different studies suggesting that posts of around 40 and 80 characters tend to get more user engagement, while another concluded that 100- to 119-character question posts performed better than the rest. That same study showed that 80-character non-question posts did just as well as 160-character non-question posts. So, ask something, would ya?
For Google+, Lee found that a headline shouldn't exceed 60 characters, which probably has less to do with how we read social media and more with the conventions of journalism — both the New York Times and the Associated Press stick to headlines of around 40 to 60 characters. Lee also points to a blog post from KISSmetrics, which asserts that the perfect headline is six words long. (Oddly, the headline of the blog post itself is 15 words.)
Lee doesn't stop with social sharing, either. He concludes that the perfect blog post is 1,600 words long, and the perfect paragraph width is around 50 characters — handy knowledge for any web designers out there.
All of this, however, seems to point to a simple rule of thumb: Twitter, Facebook, and Google+ are designed for short-form sharing, so it makes sense to keep your posts brief. In its best practices guidelines for businesses, Twitter suggests that users tend to be more engaged with tweets around 100 characters long. Importantly, however, it also notes that there is "no magical length for a tweet."
Knowing the ideal quantity of words might help you statistically speaking, but — don't forget — it's the content of those words that really counts. (Fast Company)