His tenure has seen continued adoption of broadband and ever higher Internet connection speeds, especially on the wireless side, but consumer groups saw the approval of Comcast's acquisition of NBC as a mistake, while AT&T Inc. suffered a severe blow when its acquisition of T-Mobile USA was blocked.
"For those of us who represent the public, Chairman Genachowski's term can best be described as one of missed opportunities," said public-interest group Public Knowledge. Genachowski should have done more to assert the FCC's authority over broadband, which is lightly regulated, compared with the telephone, and to prevent consolidation in the industry, it said.
In an interview, Genachowski defended the FCC's 2010 order that prohibits wired Internet service providers from blocking access to websites and services.
"We put in place the first rules to protect Internet freedom and openness, and the rules are working. We're seeing increased innovation and investment in Internet applications and services," Genachowski said. "I believe we've established an open Internet as a business and social norm in the U.S."
President Barack Obama, who worked with Genachowski at the Harvard Law Review, said he brought to the FCC a "clear focus on spurring innovation, helping our businesses compete in a global economy and helping our country attract the industries and jobs of tomorrow."
Rob Atkinson, president of the Information Technology and Innovation Foundation, a non-partisan think tank, commended Genachowski's FCC for its National Broadband Plan the first comprehensive federal plan to stimulate the availability and adoption of high-speed Internet access and for its efforts to put more radio spectrum to use wireless broadband.
"America's broadband economy is thriving, with record-setting private investment, unparalleled innovation in networks, device and apps, and renewed U.S. leadership around the world," Genachowski said Friday as he thanked the FCC's staff.
Genachowski's departure will follow that of Republican Robert McDowell, which leaves the five-member commission with a 2-1 Democratic majority until Obama appoints a new chairman and commissioner.
Stifel Nicolaus analysts Christopher King and David Kaut said they believe the front-running candidate for next chairman is Tom Wheeler, a venture capitalist and former president of two major trade groups, for the cable and wireless industries.