(Bloomberg) – The synchronized swarm of 300 drones litup the night sky behind Lady Gaga, morphing into an American flagas she recited the Pledge of Allegiance.

Sunday's Super Bowl halftime light show — prerecordedto comply with prohibitions on flying drones over people— was choreographed by Intel Corp. It provided a dramatic backdrop for theperformance and also illustrated the ways large companies areembracing unmanned aircraft in sometimes unexpected ways.

The registration of drones used for business has gone from atrickle to a flood. Only a handful were listed in the U.S. Federal AviationAdministration's aircraft registration database a few yearsago. That number swelled to 6,683 as of the end of 2016, accordingto agency records analyzed by Bloomberg.

The list of companies reads like a who's who of top U.S.corporations, along with startups seeking to catch the wave ofunmanned commerce. It comprises old-guard railroads like Berkshire Hathaway Inc.'s BNSF, utilitiesincluding Sempra Energy's San Diego Gas & Electric Co., andtechnology companies like Microsoft Corp., Amazon.com Inc. and acompany that has supplied drones to Alphabet Inc.'s Project Wing.

In December alone, Disney Co.'s TV network, ABC Inc., registered29 drones, bringing its total to 51.

37,000 more

"It does show that there is a lot of interest, and this industryis, pardon the pun, really ready to take off," Tom McMahon, aspokesman for the Association ofUnmanned Vehicle Systems International, a Virginia-based tradegroup, said in an interview.

The companies listed in the FAA's database are the ones thepublic knows about. Most unmanned aircraft now are beingregistered in a new, separate online system that the agency hasruled isn't public information. It has a total of more than 37,000additional commercial drones registered since the agency created ita year ago.

Intel, for example, had registered 112 drones in the publicdatabase, giving it the second-largest total. Those were for anearlier light show. The hundreds it has used for the Super Bowl andother recent events are registered separately in the nonpublicsystem, spokeswoman Krystal Temple said in an email. Templedeclined to say how many unmanned craft the company has in theU.S.

"Lady Gaga and the Super Bowl creative team wanted to pull offsomething that had never been done before," Josh Walden, seniorvice president and general manager of Intel's New Technology Group,said in a statement.

Because the light show was taped in advance due to restrictionson the use of drones over people, fans in the stadium could onlysee it on the video boards, Temple said.

FAA must expand the current regs

Before drone commerce can really flourish, the FAA mustexpand the current regulations that mostly prohibit flights abovepeople and over long distances, according to the Small UAV Coalition trade group. A UAV is anunmanned aerial vehicle.

"But what we are seeing, which is incredibly exciting, iscompanies are investing in this," Michael Drobac, the coalition'sexecutive director, said in an interview. The Washington-basedgroup represents companies including Amazon and Intel.

The use of drones for business has benefited from regulatorychanges. The FAA put rules in place last year allowingmore routine commercial drone flights during the day, at lowaltitudes and within sight of an operator. It also set up a waiverprocess to allow night operations or other expanded missions if anapplicant proves they are safe.

While automated drone deliveries and other far-flung uses won'tbe permitted initially, the agency is laying the foundation forexpansion. It is crafting a proposal to allow some drone flightsover people, for example.

Gaga's roof-top opening portion of the Super Bowl show, withdrones forming a star-like backdrop, also was pretaped prior to thegame and fed into the broadcast, Temple said. Fans in the stadiumhad to watch it on video, just like people at home.

Intel also produced a holiday show with Disney in Florida fromNov. 20 through Jan. 8, with drones forming a green Christmas treeand a blue dove, among other effects.

FAA process for businesses

Through the end of 2014, there had been only about 230 dronesregistered with the FAA, almost all by companies manufacturing thedevices, such as military supplier Aerovironment Inc., academicinstitutions researching them or government agencies, according toFAA data.

That began to change after the FAA created a process in 2014 forbusinesses to use unmanned aircraft. By March 2015, at least 100were being registered per month. The registrations in the FAA'spublic database peaked last May with 449.

An analysis of more than 5,500 of the initial permits grantedfor commercial drone flights issued by the FAA before the latestregulations went into effect found that most were for smallcompanies with less than $1 million in annual revenue for purposesinvolving aerial photography or data collection, according to theAUVSI.

Mapping, agriculture

One smaller company hoping to capitalize on the new industry hadregistered the most drones in the FAA's system. PrecisionHawk USA Inc., which operates drones foragriculture and mapping, listed 113 of its aircraft, beating outIntel by a single drone, according to the FAA's data.

The Raleigh, North Carolina-based company provides droneservices to companies that prefer not to own and operate them. Itsremote sensors and mapping tools can be used by insurance agentsdocumenting property damage and by farmers assessing their crops,said Thomas Haun, PrecisionHawk's vice president of globalstrategy.

The company also has teamed up with Deere & Co. toadd value to the data it collects. John Deere tractors can beprogrammed to automatically fertilize needy patches of soilidentified from drone flights.

Related: 10 risks and misuses for drones

Green MountainPower Corp., which provides three-quarters of Vermont'selectricity, has 16 drones it uses for maintenance, mostly inemergencies, spokeswoman Kristin Carlson said. It has even useddrones to check on whether osprey nests on its poles were abandonedor occupied, Mike Burke, director of field operations,said.

ABC's news division is embracing drones in a big way,said Maria Stefanopoulos, production manager for the GoodMorning America show. The network is equipping every one of itsfield producers with an unmanned aircraft so they can be used tocover disasters and other breaking-news events, Stefanopoulossaid.

A project to film a volcano in Iceland two years ago showed thevalue of mounting cameras on unmanned aircraft, she said, andthey've been used since for coverage of forest fires andtornadoes.

"We realized it was going to change the way we told storiesforever," she said.