By Nichola Groom
LOS ANGELES (Reuters) - President Barack Obama's acceptance speech on Thursday night drew the largest television audience of this year's political conventions and ranked as the biggest political moment ever on social media site Twitter.
More than 35.7 million people tuned in on three broadcast and 10 cable networks to watch Obama accept the Democrats' nomination for president, according to Nielsen ratings data.
While TV audiences for political conventions have dropped sharply over the years, Obama's TV audience was only slightly lower from his 2008 acceptance speech, which attracted 38.4 million viewers, according to Nielsen.
For Republican challenger Mitt Romney's speech last week, 30.3 million people watched on television.
On social media, the number of tweets about the Democratic convention blew away similar figures from the Republican National Convention a week earlier.
The Obama campaign has always made extensive use of social media to reach young voters and media scholar Robert Thompson of Syracuse University said Thursday night's speech was split up into seven-minute sections that made it ideal for Web distribution.
"He spoke in segments that are perfect for YouTube," said Thompson, an expert on television and popular culture at Syracuse's S.I. Newhouse School of Public Communications. "This was a speech made for use by the Democrats for social media."
The president's speech prompted 52,756 tweets per minute just after it ended, a new record according to Twitter.
The peak tweets per minute, following some of Obama's most memorable lines, exceeded all other moments for any speaker during either the Democratic or Republican conventions.
The biggest reactions came when Obama declared, "I'm no longer just the candidate. I'm the president," followed by a promise that "I will never turn Medicare into a voucher."
The Democratic convention's final day, on which Obama spoke, generated 4 million tweets, about equal to the total number of tweets for the entire Republican National Convention.
Obama gained on the Twitter Political Index, which measures how tweeters feel about a candidate on a scale of 1 to 100. The president's ranking stood at 52 on Friday, up 2 points from a day earlier. Romney's ranking stood at 9 on Friday.
On Facebook, Obama's address generated the most mentions from either convention and was 40 percent higher than the second-biggest moment, former President Bill Clinton's remarks. Romney's speech ranked fourth among most-mentioned convention events on Facebook.
Politicians also competed with pop stars Thursday night as MTV's Video Music Awards aired at the same time as the Democrats' final night. Facebook mentions of Obama, Clinton, Michelle Obama and Romney finished just ahead of British boy band One Direction, the big winner at the VMAs.
(Reporting By Nichola Groom; Additional reporting by Jill Serjeant, Lisa Richwine and Ronald Grover in Los Angeles; Editing by David Storey)