Toward the end of his 1992 campaign for president, Ross Perot ran a half-hour infomercial that was watched by 22.7 million people, according to Nielsen.
ABC did not run Obama's commercial, instead showing "Pushing Daisies," which was slightly helped by the lack of entertainment competition. The drama was seen Wednesday by 6.6 million people; its season average is 5.9 million.
Obama's spot had its biggest audience on NBC, with 7.7 million viewers.
Two months ago, Obama was seen by more than 40 million people when he delivered his acceptance speech at the Democratic National Convention in Denver. That speech was carried live on 12 networks.
The Democratic candidate also proved a late-night draw on Wednesday. "The Daily Show" on Comedy Central had a record 3.6 million viewers, when Obama was interviewed by satellite from Florida by Jon Stewart. It shattered the show's previous mark by 700,000 viewers - set earlier in the month when Obama's wife, Michelle, appeared.
"The Colbert Report" also had record ratings, when Stephen Colbert's character endorsed Obama, saying he was doing it for the attention.