This summer, I invited some neighbors over for a barbecue. We cracked open beers, threw burgers on the grill, and fired up the family drone. We peered into the iPad-connected controller streaming a live video feed--and watched the drone ascend 250 feet into the air. We could see all the way down our block, to our mailman delivering letters and some kids playing Marco Polo in their pool.

Then we hovered over our roof. One neighbor, a general contractor, pointed out some cracked shingles and--to my horror, and his delight--rust. Before I could ask him how much it would cost to fix the roof, he surprised me by asking "How much?" first: He wanted a drone of his own. His workers could then inspect houses without climbing an unsteady ladder or scaling a steep rooftop slope. Another neighbor, a real estate developer with projects all over the country, suddenly realized that she could use a drone to check in on sites and monitor progress remotely.

I'm a drone hobbyist--an anomaly, because I fly one for fun. Most drones have bigger, better purposes, and a commercial drone ecosystem is about to take off. Soon, drones will assist with everything from inspecting overhead wires to delivering packages to even building infrastructure.

For now, companies that want to fly drones for commercial purposes need approval from the Federal Aviation Administration, and drones must always be within a pilot's line of sight. Those regulations will likely change in 2016, as programmable, long-range drones that can fly 12 or more miles while carrying a 20-pound payload come to market. Unlike my drone, these new units will have sophisticated sense-and-avoid technology that allows them to navigate via GPS waypoints, to make decisions midair about the best path to take and how to dodge objects such as buildings, trees, and mountains. (And, for that matter, other drones.)

Last March, Amazon's Prime Air division got FAA approval to test its 30-minute delivery system, which will eventually serve residences and businesses in both rural and urban areas. The weekend of my barbecue, Flirtey, an unmanned-delivery startup, carried medications to a remote area in Virginia where the nearest pharmacy is 90 minutes away over winding country roads. In Switzerland and Germany, companies have tested drones that can deliver emergency supplies after a storm, when mountain paths are too dangerous for human travel.

Drones do more than make deliveries; they also collect much-needed data. AgEagle markets a yellow, wing-shaped drone that captures and stitches together infrared images so farmers  can assess crop damage. Skyfront's drone monitors long stretches of power lines and wind farm gear. Kespry's drone and software allow mining companies to automatically measure stockpiles and resources. Simpler drones could track the movement of a crowd through outdoor arts  festivals, or help a Little League coach better lead his or her young charges.

And soon drones may even help us with infrastructure projects. Engineers at the Institute for Dynamic Systems and Control and Gramazio Kohler Research programmed a set of quadrocopters to build a footbridge out of rope, which the drones, each equipped with a motorized spool, took turns weaving. The finished bridge was strong enough for an adult to walk across.

Within the next 18 months, we'll see a host of subindustries expand: drone mechanics, drone pilot schools and certifications, drone insurance providers, and marketplaces like Drone Base,  a kind of Uber for drones. I suspect we're still a few years away from a drone that can hover over  a grill to monitor when the barbecue is ready. But a girl can always dream.