Most have gone to larger companies. Companies in photography, film and real estate have received the largest share of these permits.

The biggest hurdle, most small businesses say, is that once they have the drone permit, they still need someone with a manned vehicle license — like an airplane or helicopter pilot — to fly it.

Some commercial drone fliers have not bothered to get a license. “Like Prohibition, the bar was set so high that many people have walked underneath it,” Mr. Antonelli said. But new F.A.A. rules for commercial drones weighing 55 pounds or less, to be announced as early as June, could address that hurdle.

One significant potential change would be to drop the requirement for a manned vehicle license. Instead, drone pilot certification would resemble getting a driver’s license at the department of motor vehicles, a process that could be completed in weeks rather than months.

With a streamlined process in place, the agency predicts sales of commercial drones will reach 600,000 in 2016 and climb to 2.7 million by 2020.

For now, however, the F.A.A. is cracking down on those flying without permits or who otherwise flout the rules. Last October, the agency proposed a fine of $1.9 million for SkyPan International, a Chicago-based aerial photography company, which the agency said made unauthorized flights in New York and Chicago airspace. (Without authorization, commercial drone operators cannot fly within five miles of an airport or above 400 feet.) In a response on its website, SkyPan said it had followed the agency’s rules.