By Katie Deighton

Los Angeles-based influencer agency RQ Media Group LLC is used to producing elaborate live events and parties for companies such as Alphabet Inc.'s Google and Yum Brands Inc.'s Pizza Hut, gathering Hollywood talent, journalists and influencers to promote the latest product or show.

But with social-distancing regulations forbidding many such large gatherings, the company's producers have found themselves perfecting the art of the gift box instead.

That is because large corporations are taking a slice of the money they would have spent on elaborate events and diverting it into the humble mailer -- a package that gets sent to influential people to court favor online and offline. The 2020 gift box goes beyond pre-pandemic corporate swag and attempts to shrink what would have been a multimillion-dollar live experience into an easily delivered package -- one that will ideally elicit an "unboxing" performance on social media.

"It's a safe and friendly way to really give someone an experience that they wouldn't be able to have in person right now," said Alex Diamond, director of consumer marketing at HBO, part of AT&T Inc.'s WarnerMedia division.

Just before the pandemic put a lid on big launch events, HBO promoted the third season of "Westworld" with a March 5 Hollywood screening at Hollywood's TCL Chinese Theatre and a party at the Ray Dolby Ballroom. Nearly 1,000 people attended.

Later HBO debuts in the spring and summer turned to gift boxes.

To get people tuning into the reboot of "Perry Mason," HBO in June hired RQ to design and ship mailers to cast members, influencers and fans of the show. The result was designed as a nod to the show's 1930s prohibition setting, with alcohol and mixers for cocktails delivered in milk cartons packed inside a crate.

A total of 130 boxes were shipped; 50 recipients living in L.A. also received a three-course Italian takeout from Hollywood restaurant Musso & Frank. HBO declined to comment on the costs of elaborate mailers.

RQ senior account director Katy Wellhousen said more time and strategic thinking goes into making them than the influencer kits she would mail before the pandemic.

"[Covid-19] has made me change the way I look at sending gifts," she said. "Before, I didn't find it quite as sexy as doing a live event. But now, seeing it as an experience at home rather than just a box in the mail has made it a lot more exciting for me."

On average it takes less time to design and produce a gift-box mailer than it does to organize a live event, said Max Fellows, a consultant who works with creative agencies. While some luxury boxes can cost upwards of $150 a unit to create, a flagship event can cost four-to-five times more per person for a company to produce, he said.

"You're talking about things like venues, insurance, catering, logistics and hotels, not just the creative production," Mr. Fellows said. "Live events undoubtedly cost more."

Many event producers are training themselves in the scaled-down craft of building a box to stand out among the mailer maelstrom.

A good gift box is expected to lead the recipient through an intuitive unboxing sequence that is achieved through packaging in layers, said Jerry Deeney, chief client officer at event agency Invnt Group.

He and his team had to educate themselves in box-making and design for the mailers that were delivered before the virtual reveal of the Cadillac Lyriq car in August.

"There are so many decisions you have to make around things like materials, weight, the use of magnets to keep the lid closed, and the way in which the objects are inserted and removed from the box in a way that tells a story," Mr. Deeney said.

"With a live event you're always building up to the buzz," said Zoe Lewis, head of live at London-based agency Louder Productions Ltd., which goes by the name Amplify, "but with a box the excitement of the big idea comes at the beginning and you go from there."

"Events-in-a-box" remained popular even as companies began holding live launch events in virtual form.

Wireless provider Virgin Media in July sent a group of its customers "Big Night In" boxes when the British Academy Television Awards' in-person ceremony was canceled and a virtual event was held.

Software company Adobe Inc. sent the finalists of its Experience Maker Awards a package filled with confetti, Champagne, flutes and balloons after the real-life ceremony was canceled.

"What worked about it was the quality put into it," said Katie Martell, a marketing consultant who received the Adobe box. "It came with great Champagne, high-quality stemware...it clearly wasn't a cheap endeavor."

Event planners such as RQ say pivoting to gift-box curation has helped them sustain their businesses through the pandemic, though not on the same scale as in-person events, Mr. Salzmann said.

"We wouldn't consider this a replacement for brand experiences, but during the current crisis it certainly is doing its job," he said.

Write to Katie Deighton at katie.deighton@wsj.com