Some in the ad industry are calling Oscar winner Matthew McConaughey's multiyear deal to star in Lincoln car commercials "a watershed" in breaking the taboo against A-listers in TV commercials. Reuters

Yes, that's Matthew McConaughey in a Lincoln Motor Company ad shilling for its MKC luxury SUV. And yes, you're right to think that's strange.

For years, A-list Hollywood treated TV commercials with extreme caution. While many felt free to shill products abroad -- a phenomenon illustrated by Bill Murray's character in the 2003 "Lost In Translation" -- TV ads were thought to be beneath serious movie stars. But McConaughey's presence is the most brazen indication that there’s not much of a taboo left, signaling a change in the notion of celebrity and the growing cachet of TV. What's more, “selling out” means little to many young people who’ve grown up with the idea of the celebrity endorsement and the understanding of celebrities as brands.

There just isn't a stigma to doing TV, or commercials on TV, anymore. Today the public understands celebrities as brands, and an appearance in a commercial is just another way of extending it.

Watershed moment

“This one breaks the seal,” says Doug Shabelman, president of Burns Entertainment, a company that plays matchmaker between brands and celebrities. “McConaughey is at the height of his popularity. He’s an Oscar winner, an international, big-name star. It’s a watershed moment.”

The rise of the Internet and oversharing means that a star, who was once defined by his or her distance from the public and the mundane, needs to compete for visibility with not only reality TV stars but also every oversharer on social media. A commercial, particularly a well-done one, can be a means for self-promotion or the promotion of a project – and the star can get paid handsomely for it.

Lincoln, according to AdAge, has contracted McConaughey to win a "younger, more progressive" consumer. The TV ad you've probably seen by now is just the beginning: The deal is multiyear and will include digital spots created by Danish director Nicolas Winding Refn that attempt to get viewers to experience the MKC through "unscripted moments" with McConaughey.

McConaughey isn't the first, but the combination of his star-power and the size of the campaign make his deal a milestone. Although Clint Eastwood starred in a Chrysler ad that aired at the Super Bowl in 2012, Brad Pitt starred in much-parodied Chanel perfume ad the same year, and Charlize Theron has been in a number of ads for Dior’s J’Adore perfume, just to name a few celebrity endorsements, these were mostly one-offs or alliances with fashion brands, which has a long history in Hollywood.

Movie stars don't do ads

When brand strategy consultant Eli Portnoy of Miami’s CultureRanch worked in product and consumer management in the 1980s, getting a movie star to endorse a consumer product – shampoo, soap, cosmetics, cars – was out of the question.

“If we approached movie stars,” he said, “we were told by their agents, ‘They don’t do ads in the U.S.’” TV stars like Linda Evans, however, gladly endorsed products, and could often get paid a million dollars. “That was a ton of money then [in the '80s],” he said. But the only movie stars who ever starred in commercials were “either past their prime or almost dead.”

The shift has been underway for more than a decade. In 2001, the New York Times reported that the stigma against endorsing products was beginning to fade, signaled by the increase in movie stars who were beginning to endorse fashion and beauty products at the time. "As the line between art and commerce continues to erode,” wrote Ruth La Ferla, “the role of pitchperson is clearly losing its stigma.”

Jonathan Perry, at the time a former Hollywood publicist turned L.A. talent agent, was quoted as saying, "Five years ago” – which would have been around 1996 at the time of publication -- “publicity stopped being an appearance on TV and started being a marketing scenario.”

Something else happened about that time: The celebrity category known as the "supermodel" -- which arose in the '90s -- was usurped by Hollywood actresses. In no time, model’s faces on magazines were replaced by celebrities’, a trend that hasn’t much reversed in two decades. In the 2001 Times piece, Perry noted, “'It's reached a point now where models have a more and more limited marketplace.''

True Detective

Which brings us to McConaughey’s series of commercials for Lincoln. In them, he’s clearly evoking his “True Detective” character, alone, driving, and musing about life. Why is a movie star hot off an Oscar win and a critically acclaimed HBO series “True Detective” shilling a car? He doesn’t need the money, and he doesn’t need the visibility – but he might need, as the kids say, all of the visibility. With the rise of the reality TV star, the Paris Hiltons, Kardashians and Real Housewives – and the collapse of the old-school distinction between a movie star and everyone else – celebrities have to up their game to get themselves out there.

“These days a celebrity has more pressure to stay relevant and in the public eye," said Shabelman. "Celebrity now means different things. There are reality television stars, celebrity chefs like Bobby Flay. Yes, celebrities endorse products because there’s money there, but they also do it to stay in the news. It’s a way of remaining visible, a way of extending stardom. Stars still don’t want to overdo it, and some want foreign ads to remain there. George Clooney, for example, still doesn’t really want his ads in the U.S.”

The ascent of TV

Then there's the ascent of TV as an art form. Arguably, the best dramas have been happening on television, from “The Wire” to “Treme” to “Breaking Bad,” which even earned its star Bryan Cranston a letter from Sir Anthony Hopkins telling him the ensemble cast showed the best acting he’d ever seen his entire career. “There used to be a sense that TV actors were second-level celebrities,” said Portnoy. “Not as rich or inspiring. But so many very important actors have created excitement over cable and pay channels.” As a result, the taboo of a movie star doing anything on television has been lifted.

The Internet, YouTube, Instagram and Twitter has also created a culture of oversharers. As a result, there’s almost a demand that celebrities put themselves out there. “The Internet broke down all the barriers," he said. "Old celebrity was defined by distance. New celebrity is defined by presence, being in your face. Culturally, with the advent of the Internet and sharing, the special 'outside' is gone.”

All of this talk about the collapse of boundaries doesn't mean, however, that we're entirely comfortable with the idea of seeing a movie star in a commercial -- primarily because of the confusion about exactly what we're watching. "When I saw the ad, it stood out as weird, but at first I couldn't figure out why," said Professor Catherine Zimmer, Director of Film and Screen Studies at Pace University in New York City. "I couldn't tell if I was watching Matthew McConaughey starring in a car commercial or in a promotional trailer for 'True Detective.' "

When Ellen DeGeneres was setting up her spoof of the Lincoln ad recently for her audience, uncomfortable laughter could be heard in response to the real commercial, before she showed her spoof. Is Matthew McConaughey promoting a new episode of “True Detective"? A spoof of “True Detective"? Is Matthew McConaughey in a Lincoln car commercial? Or, as the voiceover indicates, when Matthew McConaughey tells us “I’ve been driving a Lincoln long before anyone ever paid me to drive one. I didn’t do it to be cool. I didn’t do it to make a statement. I just liked it,” is he just sharing a personal truth with us, letting us in on the life of Matthew McConaughey? The fact that the answer can be “yes” to all questions says it all.