Trending topics are the holy grail of Twitter marketing/outreach. You can buy your way to the top, but how are those topics that aren’t paid for moved to the top of the list? HINT NUMBER 1: Have something to do with Justin Beiber… seriously.

For a more academic look at what goes into creating the trending topics, read this PDF:
Trends in Social Media: Persistence and Decay

via Gizmodo via Mashable via NYTimes