Fast Company reports on the results of a study by Hubspot viral marketing scientist Dan Zarrella.  Zarella spent nine months analyzing over 40 millions tweets and 5 million retweets to find commonalities among the most prolific retweets.  From this mound of data, nine lessons were discovered:

1. Always shorten your URLs but don’t use Tinyurl.com to do so.  Apparently bit.ly is the most popular URL shortening service (probably because it’s Twitter’s default).  The older services such as tinyurl.com tend to have longer URLs which eats up precious characters.
2. Mind your Ps and Qs.  Polite requests to “retweet” tend to work among Twitterers.
3. Avoid TMI.  Tweets that provide insight into the mundanes of your life are to be avoided.  Nobody wants to know that you’re bored, what you ate for lunch, or that you’re watching TV.
4. Raise your grammatical standards.  Retweets tend to be of a higher education level for understanding that non-retweets.
5. Punctuate but avoid semicolons.  Most retweets contain periods, exclamations points and other punctuation but those with semicolons ranked at the bottom.
6. Be original.  Retweets that broke news or provide original content were retweeted far more often.
7. Use proper nouns.
8. Don’t be emotional.  People don’t retweet your bad moods.
9. Friday afternoons are more than just daydreaming about the weekend.  The frequency of retweets seems to peak at 4pm on Fridays.

To see more of the data and analysis visit: Report: Nine Scientifically Proven Ways to Get Retweeted on Twitter