Zarrella says in a post
I found that Tweets between 100 and 115 characters were 34% more likely to be ReTweeted than Tweets outside of that range, with a 99.9% confidence interval. A big drop off in ReTweet probability occurs once Tweets get beyond about 120 characters, but up to that point, the longer the Tweet, the better.
So the high water mark is 120 characters. Can you restrict yourself to that limit on a consistent basis? Do you even agree? Do just a few more characters make it too long for people to read and share? Is it because anything longer might not let the retweeter add his or her’s two cents? God forbid!