The first lady's Tuesday night address in Charlotte, North Carolina, was watched by 26.2 million Americans across nine cable and network channels, according to final Nielsen data.
That was 4 million more than tuned in for the 10 p.m. hour a week ago to hear Ann Romney speak about husband Mitt, Obama's Republican challenger in the November 6 presidential election.
The TV audience was also 4 million more Americans than watched the first day of the 2008 Democratic National Convention, but below the 30.3 million who watched Mitt Romney's prime time address from Tampa last week.
In social media, reaction to Michelle Obama's speech was off the charts, and Twitter was packed with messages wondering whether she would one day run for the highest office in the land herself.
Mrs. Obama racked up 28,000 tweets per minute at the conclusion of her speech on the opening night of the convention, according to Twitter. That was double the 14,000 that Mitt Romney saw in his convention speech in Tampa, Florida, last week. Ann Romney's tweets per minute tally was just over 6,000.
CNN anchor Wolf Blitzer said the first lady had scored "not a home run but a grand slam."
Mark Iafrate, creative director for online tracking firm General Sentiment, said Michelle Obama was "the most discussed person at the DNC," next to the president himself.
Twitter hashtags #michelleobama and #firstlady were among the top five trending topics on Tuesday night. Mrs. Obama's Twindex score, which measures tweeters' feelings about a political person, rose from 71 before the speech to 84 immediately afterward.
President Obama got an even bigger boost. His Twindex score rose from 25 before his wife took to the stage to 54 immediately afterward. Traditional opinion polls, however, continued to show Obama and Romney in a tight race.
In a canny move, the White House put out a cozy photo of Obama and his two daughters curled on a sofa listening to Michelle's speech. The photo had notched more than 171,000 views by Wednesday afternoon, making it by far the most popular White House photo in months.
Comedian Chris Rock didn't hold back on Twitter: "I'm ready to vote NOW dammmit! Where's the ballot? What day is it? Where am I? Who am I? Michelle OBAMA ladies & gentlemen. wow."
Many others looked beyond the mom-in-chief mantle that Mrs. Obama has assumed.
"I think we need to stop comparing Michelle Obama's speech to first lady speeches and start comparing it to presidential ones. That strong." said Twitter user Heidi N. Moore.
"Screw it, make Michelle Obama the president of the whole damn world," said David Robert on the microblogging site.
Copyright Thomson Reuters 2012