It's easy to follow an influencer on Twitter. But don't stop there. Who provides the biggest audience when others reply to that influencer or re-Tweet their material? Even better is to know who a given influencer replies to. That could lead you to entirely new influencers.
Peter Kafka, Blogger
After a decade at Forbes and a shorter stint at Silicon Alley Insider, Peter Kafka brings his considerable reporting skills to the Wall Street Journal's popular web site, AllThingsD. Kafka specializes in tracking the media business and all companies that affect it -- especially those based on the East Coast.