Although politicians are stepping up their use of the Web, some experts doubt the medium's ability to win undecided voters or get voters to cross party lines. "The Internet is great for fundraising and for rallying your supporters, but I'm skeptical that it can be used to convert--to persuade people," says David Dulio, an associate professor of political science at Oakland University. "I just don't think the power is there for it yet." Dulio points out that the 1,800 people who demanded that Edwards come to Columbus are an infinitesimal number compared with the 120 million people expected to vote in the next election.

Others think that sites like Eventful could change the nature of political engagement. "What sets Eventful apart is its ability to predict or showcase a demand in advance," says Andrew Rasiej, who has advised candidates including Hillary Clinton and Howard Dean on using technology in their campaigns, and is founder of the website techPresident, which tracks how presidential candidates use the Internet. When a group of people create a demand, he explains, it is a visible sign of interest in a potential event. This information can then be used to coordinate actual events. Compared with social-networking sites such as Facebook, Eventful "is probably more tied to the holy grail of online politics, which is converting online enthusiasm into offline action," Rasiej notes. He points out that people who make a demand are not merely putting a tag on a profile page: they're promising to show up at an event when it happens.

Rasiej says that candidates should pay attention to social-networking sites and other online services that can become part of a campaign. "The most important thing is that candidates have to recognize that all these tools have positive and negative consequences, which is all the more reason why they have to develop very savvy Web strategies and an ability to execute them," Rasiej says. Campaigns need to respect the power of the infrastructure that voters have built up online, he says, adding, "It wasn't so significant that [Edwards] went to that town; it was significant that he acknowledged the collective voices of the crowd."