Under a bright blue Florida sky, Breanna Banaciski stood in front of a mansion, looked into the video camera she’d mounted on a tripod and began her pitch. It opened in a tone of feigned exasperation.

“This is getting ridiculous. This house is 7,000 square feet. I can’t even fit it into the frame,” she said, bleeping out an obscenity before “frame.” “Five bedrooms, six bathrooms, 3.5 million dollars.”

Smash cut to Ms. Banaciski lying on the ground, as though the sheer extravagance of the words had killed her.

Cut to her standing in a large bedroom.

“This house keeps going and going and going. It doesn’t end!” she shouted, sounding annoyed. “It’s like the ‘John Wick’ series.”

Moments later she’s gesticulating in a huge room filled with shelves and cabinets.

“What do rich people do with a closet this size?” she asked, as though someone really wanted to know. Answer: “This is where they store their tax write-offs.”

There’s a “Titanic” joke, a Diddy party reference, an R-rated quip about the disappointing size of the swimming pool. She wraps by urging viewers to tell friends about this place, though only if they cannot afford it. Because it will bug the [bleep] out of them.

If you didn’t know better, you might think this 1-minute-and-13-second clip was a profane and withering satire on wealth inequality, performed by a comedian who swiped the keys to a one-percenter’s home. Actually, Ms. Banaciski is a licensed real estate agent, and this video clip is an authentic advertisement for that mansion in Belleair, Fla.

Ms. Banaciski has ditched the upbeat cheerfulness that is the industry’s default tone and brought sarcasm and zingers to the world of residential real estate. She would dearly love to make a sale and earn a commission, but first she’s going to make you laugh.

“That’s just my personality,” she said in a phone interview. “I make jokes.”

Barbed humor and real estate, it turns out, are a potent combination. Ms. Banaciski, 30, has won a huge audience on social media — about 2.7 million people watched the video for the Belleair property on TikTok, where she has 328,000 followers. (She has slightly more on Instagram.) And while a vast majority watch for the yuks, a surprising number get in touch.

In a Tampa market that is struggling, Ms. Banaciski has been inundated with calls from people shopping for a home. So many, in fact, that she’s handed off dozens of leads to colleagues at the real estate firm where she works, the Lutz, Fla., office of Realty ONE Group Advantage. To date, she’s sold three homes and has four under contract, a very strong start for an agent who got her license late last year, said Dara Khoyi, the broker owner of Realty One.

“She’s an up-and-coming agent,” he said, “who looks like she’s going to set some records.”

Ms. Banaciski, who lives with her fiancé in a Tampa suburb, saw none of this coming. She started posting comic videos in March. Before that, she’d taped a few mirthless virtual real estate tours and was irked when fewer than 200 people watched them. So she unleashed the funny in a video tour of a newly constructed, five-bedroom home in Lutz.

“I could never live here. One, because there’s a dead bug on the floor,” she said, pointing at the offending insect on the carpet. “And two,” she added, turning to look over the interior balcony and down at the first floor, “I don’t like heights.”

To the consternation of her boss, she didn’t originally bleep out the four-letter words.

“She’s toned it down a bit, and I’m happy with that,” said Mr. Khoyi. “Whenever I need a giggle now, I look at her Instagram posts and laugh my head off.”

People find her videos when they search for real estate in Florida, and she’s now popping up in the feeds of comedy fans. A handful of television production companies have come calling. In June, she signed with a manager in Hollywood, Lee Kernis, who’s worked for decades with stand-up comedians and writers. He and Tornante Television, the studio behind “Bojack Horseman,” are trying to conceive a show built around her.

“You can watch a bunch of brokers imitating her online now and they don’t have a clue,” Mr. Kernis said. “She can write a joke and she knows how to edit so you get in and get out fast.”

Comedy and acting have been Ms. Banaciski’s passions since she was a child; if she’d had the money, she would have followed the advice of a drama teacher who urged her to drop out of high school, move to a major city and try her hand at showbiz.

Ms. Banaciski tours these lavish homes with an outsider’s disbelief that is only partly a shtick. She grew up with five siblings in a home in a blue-collar Florida suburb. The electricity was occasionally shut off, and condiments were sometimes the only food in the refrigerator. Her father was a car salesman at a Honda dealership, and if he didn’t move any merchandise, he took home a very small salary.

She skipped college, fearful of assuming $50,000 worth of student loans. She cycled through a series of jobs — at Kmart, at Busch Gardens, at the Kennedy Space Center, where she snapped photos of visitors. She spent a few years in the motor vehicle section of the Pasco County tax collector office, earning $12 an hour.

When a guy approached her window and told her that he’d just bought a Subaru, she shot back, “Well, that’s your first problem.”

She later worked for a semiconductor company that sold to manufacturers of circuit boards. For years, she cold-called potential customers. When that got tired, she wondered if she could turn her downtime passion, browsing homes on Zillow, into a job.

Before her videos caught on a few months ago, buyers were so scarce she thought about quitting. The number of people moving to Florida is still larger than the number who are leaving, but the inflow has dipped considerably from a few years ago, said Chen Zhao, head of economic research at Redfin. At the same time, the Multiple Listing Service database shows 10,000 to 15,000 new listings every week, roughly four times the historical norm, said Philip Simonetta owner of Pier 21 Realty.

“A lot of people are trying to cash out their equity because they’re afraid of it going away as the market is coming down,” Mr. Simonetta said. “Prices in parts of Florida are off 13 percent.” High interest rates are a huge part of the problem. Hurricanes and flooding, made worse by climate change, have led to a sharp increase in the cost of homeowners insurance.

Comedy chops and social media algorithms have allowed Ms. Banaciski to thrive nonetheless. Sellers of homes worth $1 million and more get in touch because they want the insult comic treatment. They don’t want a roasting for its own sake, but because Ms. Banaciski’s videos can multiply the number of virtual visitors by a factor of 1,000.

During in-person tours with buyers she is freewheeling and largely unfiltered, though she dials back the put-down jokes. Customers call her because she’s acquired a bit of internet fame and because her unvarnished style implies a kind of radical honesty.

“She’s so upfront about everything,” said Michael Plourde, a buyer from Kansas who is searching for a home in Tampa. “It automatically made me trust her.”

Management at Realty ONE does not vet her videos. The only guardrails she abides by are matters of law. Fair Housing restrictions bar real estate agents from describing neighborhoods with terms like “safe” or “up and coming.” That’s a no-no because it implies a preference for or against a certain type of buyer.

Playing by the rules leaves plenty of space for her to antagonize just about everyone — including owners of oversized vehicles.

“This carport is tall enough to fit your jacked-up F-150,” she said at the start of a video for a three-bedroom home in Tampa, “but not tall enough to fill the void of when your father left.”