Koreas expert Scott Snyder said he expected Pyongyang's propaganda machine to capitalize on the visit.
"It would not be surprising if next week the North Koreans were to air a prime time feature on the Google chairman's trip, with lots of pictures of the delegation visiting premier North Korean facilities and other attractions," said Snyder, a senior fellow for Korea studies at the New York-based think tank Council on Foreign Relations.
Richardson said the message about expanding the use of technology in North Korea was very "well received."
He said the delegation strongly urged the government "to proceed with a moratorium on ballistic missiles and a possible nuclear test" and that they had "very frank discussions" with North Korean officials about the current tensions on the Korean Peninsula.
Richardson said the North Koreans were encouraged by recent statements by the new South Korean leader, President-elect Park Geun-hye, who has said she will make efforts in her five-year term to boost aid and engage with the North.
Richardson said they also expressed concern about an American detained in North Korea, and were told his health was good and that judicial proceedings would start soon. Pae Jun Ho, who is known as Kenneth Bae in his home state of Washington, is a 44-year-old tour operator of Korean descent who was arrested in November in the northern city of Rajin.
"The delegation's trip to North Korea was productive, was successful," Richardson said at the airport in Beijing, adding that the group was invited to return. "We do expect to go back."
There are no major U.S. firms operating in North Korea, which fought against the United States in the Korean War of the 1950s. The foes signed a truce in 1953 to end the fighting, but never a peace treaty, and the two countries still do not have diplomatic relations.
Even if Schmidt wasn't officially representing Google in North Korea, the company stands to benefit if the country's leadership loosens its Internet restrictions. For years, the Mountain View, California, company has pushed for more accessible and affordable Internet connections and Web-surfing devices on the premise that its business ultimately will make more money if people spend more time online.
Associated Press writer Jean Lee in Pyongyang, North Korea, and Youkyung Lee in Seoul, South Korea, contributed to this report.