Many U.S. agencies don't have the resources or the ambition to open up a two-way conversation with constituents, said Maura Corbett, a partner in Qorvis Communications, a Washington, D.C., public relations agency with several tech clients. The Obama administration "can't empower citizens to participate if their own agencies don't," she said. "That's the harder job. You can have the best plan for open government and communication, but most federal agencies don't have the tools to do it."

In addition, campaigns are exciting, but day-to-day government can be tedious, Corbett noted.

"In a campaign, Twitter and Facebook and YouTube and that kind of stuff is really fun and exciting," she said. "Doing it for the process of government is incredibly boring. You're going to use all these 21st-century, cutting edge, social-networking tools to watch sausage being made.

"It's very hard to make tax policy Twitter-able."

Many early attempts at crowd-sourcing -- using large groups of people to drive ideas forward -- saw crowds disappear quickly, said Forrester's Townsend. "You get these huge waves of participation, but it's not sticky," he said. "Attrition is a huge problem."