Amid the tributes to Kobe Bryant on Sunday — dedications at the Grammy Awards, condolences from presidents, messages written on the sneakers of N.B.A. players — there was a Twitter post from the blockchain company Tron Foundation.
“Kobe is a member of the TRON Family,” it said. “As such, we will be dedicating @niTROnSummit’s festivities to his legendary life & legacy.”
Mr. Bryant’s only public interaction with the company was a speaking engagement at its 2019 conference, and the replies to the tweet were filled with complaints calling Tron opportunistic for capitalizing on what seemed to be a tenuous relationship so soon after he was killed in a helicopter crash with eight others, including his daughter Gianna.
The negative reaction suggested that companies must be tactful as they try to memorialize Mr. Bryant. A hasty social media post can bring accusations that they are trying to cash in at a sensitive time.
“There’s no playbook for this one; the sponsors are going to tread incredibly lightly,” said Jeremy Carey, the managing director of Optimum Sports, the sports media and marketing division of the advertising giant Omnicom Media Group. “It’s all too soon.”
Justin Sun, Tron’s founder and chief executive, said his company’s tweet was heartfelt. “I totally understand that there will be different voices from the community, but this is from the bottom of my heart, needing to do the right thing,” he said. “No matter what, we needed to pay tribute to him.”
Like an earlier on-court superstar, Michael Jordan, Mr. Bryant was a gifted marketer away from the game. He earned more from his deals with companies than he did from his salary, according to Forbes, and his success helped shape how current players like LeBron James and Stephen Curry navigate the celebrity endorsement business. Mr. Bryant was a student of the discipline as well, as he showed when he sat in on an international marketing class at Boston College in 2014.
These days, companies have made themselves relevant to customers by quickly responding to news cycles. When an installation featuring a banana taped to a wall at Art Basel drew an intense social-media reaction, companies pumped out online parody ads. When Tesla found itself trending on social media after unveiling its Tesla Cybertruck, Lego posted a photo making fun of it. And shortly after Twitter users deemed a recent Peloton commercial sexist, the “Deadpool” star Ryan Reynolds pulled together a response ad for his Aviation American Gin company.
But companies have learned through hard experience to be cautious when it comes to news cycles dominated by celebrity deaths. In 2016, the footwear maker Crocs drew complaints after marking David Bowie’s death with an image of a lightning bolt, inspired by the musician’s “Aladdin Sane” album cover, layered over a white shoe. The Mexican airline VivaAerobus drew similar outrage for posting a photo of a similar lightning bolt on a plane.
Later that year, to mark the death of Prince, Cheerios posted an image of the words “Rest in peace,” with a single Cheerio dotting the “i” in the word “in.” After a backlash, Cheerios hit delete. Maker’s Mark went with an image showing the distinctive red top of its bourbon bottle turned purple, Prince’s signature color. Annoyed fans noted that Prince did not drink alcohol. Other companies, including 3M, Getty Images and Pornhub, were also accused of exploiting his passing to promote their products.
Other companies, especially those that worked with Mr. Bryant, opted for a milder approach: a black-and-white photo paired with a statement honoring his life and expressing concern for the families of the victims.
Nike, which has been linked to Mr. Bryant for nearly two decades and helped popularize his “Black Mamba” nickname, cited his “immeasurable impact” and made no mention of a recently updated sneaker design called Kobe V Protro Chaos.
Adidas, which sponsored Mr. Bryant when he was a teenager and produced shoes in his name, described him as “a true legend.” The BodyArmor sports-drink maker said Mr. Bryant, a significant investor in the company, was “an incredible friend.”
McDonald’s, which let a sponsorship deal with Mr. Bryant expire after he was accused of sexually assaulting a woman in 2003, posted a message “honoring his greatness” on a corporate Twitter account devoted to McDonald’s All-American Games, a high school basketball tournament.
Sprite, which stopped running ads featuring Mr. Bryant after the 2003 accusation, did not publicly comment on his death. (The criminal case against Mr. Bryant was dropped in 2005. He settled with his accuser, and the terms of the settlement were not disclosed.)
Several organizations without ties to Mr. Bryant have also accommodated the news. Planters announced that it had paused its pre-Super Bowl paid-advertising campaign, a stunt featuring the mascot Mr. Peanut dying in a car crash. Google, Mountain Dew, Olay and Pop-Tarts pushed back plans to reveal their ads for the Super Bowl.
“You want to be sensitive at a time like this,” said Shaina Wiel, a longtime marketing professional who founded the Minorities in Sports Business networking group. “It’s part of a larger conversation: How do brands fit into these situations?”
Marketing was central to Mr. Bryant’s public persona. Commercials portrayed him as goofy and approachable. He lip-synced to Bob Seger’s “Old Time Rock and Roll” alongside other sports stars for a Guitar Hero ad in 2008. He tried to one-up the soccer star Lionel Messi in a Turkish Airlines spot that was voted YouTube’s ad of the decade in 2015. He let Apple describe him in a cheeky ad in 2016 as being “locked in a battle with Father Time.”
He started Granity Studios, a multimedia company focused on sports-related content, and won an Oscar for an animated short film. He co-founded Bryant Stibel, an investment firm, and funded companies like the Fortnite maker Epic Games. And he encouraged children to pursue sports in an ad for Project Play, an initiative from the nonprofit think tank Aspen Institute.
Now fans are petitioning the N.B.A. to change its logo — inspired by another former Lakers star, Jerry West — to feature Mr. Bryant’s image.
“He created this gray area, establishing that it wasn’t just about stamping his name on a pair of shoes,” Mr. Carey said. “He changed the game for a lot of athletes. He set a new bar for business beyond basketball.”