Trends in Social Media: Persistence and Decay Click to view The researchers analyzed 16.32 million tweets on 3,361 different trending topics between September and October of last year to figure out just what made a topic trend. The key: retweets, especially retweets by power news accounts like @nytimes or @breakingnews. Less important are sheer volume of tweets, or tweets from celebrity-type "influencers."
The full report above walks you through the methodology in more depth, with lots of fancy mathemagics and such. But the main takeaway: trending topics are fleeting as the wind, while the accounts that make them are as venerable as stone. [Mashable]