Of all the technological innovations that marked the 2008 presidential campaign, one of the most important was YouTube. Four years earlier, the service didn't even exist, but by 2008 it had hosted thousands of political videos. It can be hard to keep up with that kind of technological explosion.

In April, the University of Massachusetts-Amherst hosted a multidisciplinary academic conference called "YouTube and the 2008 Election Cycle in the United States." The conference featured deep research into how candidates used YouTube and how it affected the election. It's perfect information for campaigners and consultants—but the kind that frequently slips under the radar of the political consulting world. That's why we've grabbed the authors of four of the best papers and asked them to explain just what it is that you need to know about YouTube for your next campaign.