NEW YORK (October 17, 2012)--The 90-minute nationally televised exchange Tuesday night between President Barack Obama and Republican Mitt Romney generated 12.24 million comments on Twitter and Facebook according to Bluefin Labs, an analytics firm that studies social media's reaction to televised events.

The end of a tense exchange over immigration Tuesday night produced the biggest social media spike.

The debate was the top political event of all time in social media and placed third among the top social media events of any kind, topped only by this year's Grammy Awards and MTV Video Music Awards.

The first presidential debate, on Oct. 3, placed fifth.

Women dominated the social media conversation about the debate. Some 54 percent of all the comments came from women, 46 percent from men.