The Social Security Administration broke into the e-government top 10 with the addition of three new sites to the index, according to Freed. The sites -- the SSA's Help With Medicare Prescription Drug Costs, Internet Social Security Benefits Application, and Social Security Business Services Online -- each do a good job of meeting the specific needs of its user base, Freed said.

"E-government has been making incremental improvements on a consistent basis, and over time these incremental improvements continue to add up," Freed said.

"Online government is nearly keeping pace with the private sector, but government is doing it with much more limited resources," he said. "Measuring customer satisfaction is the first step in identifying where improvements are needed, but some government sites may not have sufficient budget to make changes that will result in customer satisfaction increases."