"It was a great move," Sean Cassidy, president of the PR firm DKC, said. "They both have products to promote right now and one thing Trump knows better than anybody is that controversy sells. You need to be that much more intense to break through all of this online and tabloid chatter," he told Sunday Morning correspondent Martha Teichner.
"On the other hand, the significance of it, or the impact of this is less because there's so much more of it."
Trump has had his share of feuds — with his ex-wives Ivana and Marla Maples and also Martha Stewart. Then there was the battle between Tom Cruise and Brooke Shields over the use of antidepressants; basketball players Shaquille O'Neal and Kobe Bryant; and just about every rap star with every other rap star.
Michael Musto greedily devours feuds. He's the author of "La Dolce Musto," a collection of his snarky celebrity gossip columns from the Village Voice.
"So much of my job involves chasing celebrities and trying to get something dramatic out of them; something beyond the same old, boring, 'My new movie is a labor of love' type of item that provokes nothing but yawns," he said. "So when the two celebrities like go at each other and provide the drama and conflict, you just want to sit back and go, 'Yeah. Thank you! Go there. Roll around in the mud. Give me good copy, bravo!"
While all these feuds swirl around us, the world is embroiled in some serious conflicts. There's a war in Iraq and Afghanistan, but Trump and O'Donnell consume headlines. The reason, according to syndicated radio psychologist Joy Browne, is that these fights distract and entertain us during troubled times.
"I would probably argue that if the world was a safe and comfortable place that we probably wouldn't care as much about Rosie and The Donald," she said.
After more than 20 years of listening to non-celebrities going at it, Browne says television has changed the way Americans feud.
"I think TV has shown us exactly how to do it and not only how to do it but the rewards for it, of the audience applauding, using foul language, tears, the whole thing. Yeah, they've shown us exactly how to do it — it's sort of Feud 101," she said.
Except that unlike the made-for-TV feud, when we do it, the pain is real.
"Let me say I think every family probably has a potential feud," she said. "And my point about feuding is that there's really no pay-off — everything gets settled at the peace table anyway, and all you have with a war is body parts littering a sidewalk."
Just look at history, in the case of the feud between England's Queen Elizabeth I and her cousin, Mary Queen of Scots, who lost her head. In the 16th century Galileo and Pope Urban XVIII fought over whether the Earth revolved around the Sun or vice versa. Galileo was right but he spent the rest of his life under house arrest.
Hal Hellman has written four books about great feuds and said memorable feuds usually include well-known people.
"It could be the level of the subject, of the problem that they have been working on, something that's fascinated the world perhaps," he said.
Consider the nasty, very public feud involving Dr. Jonas Salk, the man who developed the polio shot, and who ended up feuding with another doctorm Albert Sabin, who came up with another form of vaccine.
"Sabin said early on that what Salk had done could be done in a kitchen, anybody could do that. Sabin accused Salk's vaccine of causing polio. Salk accused Sabin's of causing polio," he said.
They railed against each other for years, and neither won a Nobel Prize.
Philo T. Farnsworth invented television, but he died broken and broke after battling RCA chief David Sarnoff for more than forty years. Farnsworth claimed RCA had pirated his technology and robbed him of fame and fortune.
"You'd think that these enormous intellects, these geniuses would be above feuding," Hellman said. "Scientists, mathematicians, whoever I worked with, they're also human beings."
But as Muhammad Ali and Joe Frazier proved, feuding can make you a winner, even if you lose the fight. The two of them mouthing off at each other turned their three fights into possibly the greatest boxing spectacle of all time. The public loved it.
But sometimes feuds backfire. Cassidy thinks Tom Cruise went too far.
"This jumping on the couch and the attacking Brooke Shields, the whole stuff with Matt Lauer, that was great for 'The Today Show,' but certainly made Tom look a little strange. It hurt him. It hurt him because, again, it was inconsistent with the Tom Cruise brand."
Some people die hating each other. There was that quintessential American feud: Joan Crawford and Bette Davis. They weren't just acting in "Whatever Happened to Baby Jane" — they actually hated each other.
These two aside, Browne says people can get over their longstanding feuds.
"If you can find that without acknowledging the past and without the need for an apology, quite often, you can mend feuds," she said.
So how exactly would O'Donnell and Trump go about doing that?
"I have every certainty that The Donald will appear on 'The View' and it will be the highest rated episode of 'The View' in history," Musto said. "And they will pretend to make up. Rosie will still be a little bristly, Donald still be a little bully-ish, but they're going to bury it for the public's delectation."