Articles such as the one below certainly point to the likelihood...

Articles such as the one below certainly point to the likelihood of airports being amongst the earliest clients.

http://www.dw.com/en/air-controllers-report-40-incidents-of-drones-near-passenger-planes/a-35886551

German air traffic controllers have noted dozens of incidents with drones in recent months. Flying toys have been directed dangerously close to passenger planes. Controllers want to make drone pilots take a "flying" test.

German authorities have recorded over 40 cases involving drones since the beginning of 2016, air traffic controllers said on Sunday. It marks a sharp jump from last year, when only 14 incidents were noted during the whole year.

Some passenger planes managed to avoid midair collisions "at the very last moment" with drone pilots flying their machines ever closer to the large aircraft, according to an article published in the Sunday edition of the "Frankfurter Allgemeine Zeitung" newspaper.

The numbers provided by the air authority do not include incidents involving emergency helicopters, the paper claims.