How long will it be, do you think, until companies such as Amazon start delivering packages to you by drone?

If that prospect seems fantastical to you, you are not alone. According to a survey published last week by the U.S. Postal Service's Office of Inspector General, 57 percent of people are either neutral about it or think it's a bad idea. Seventy-five percent of people think drone delivery is five years away at best; the rest think it will take even longer, if it happens at all.

There are some good reasons to think this timeline is accurate. For one thing, the survey shows the public's skepticism of the technology. That finding, which has been expressed in policy as a relatively slow approach to drone testing, helps shed important light on how technology adoption works more broadly.

In its questions, the Postal Service OIG asked respondents how they would feel about companies such as Amazon, United Parcel Service and even the Postal Service if they decided to offer drone deliveries today. And the results were unequivocal: Every brand's reputation would suffer, suggesting there is a long way to go before drone deliveries take off with consumers.

If these numbers are right, it suggests that some of the biggest barriers to drone delivery might actually be perceptual as much as technological.

Many other countries are moving ahead with drone testing, while the United States only recently gave companies the green light to begin limited tests, according to Michael Drobac, a legal expert on drones at the law firm Akin Gump Strauss Hauer & Feld.

"What appears to be science fiction or many years off is actually happening — just not here," Drobac said.

This gap between public receptiveness to a technology on the one hand and the actual state of the technology on the other can be found in other industries, too. So for the idea to really take off once the final technological and regulatory hurdles are overcome, companies will need to convince consumers that it will actually improve their lives — or suffer a blow to their reputation.

"The usual history is people are pretty content with what they know, what they have, and adopting an innovation does take substantial effort," said Ben Shneiderman, an expert on human-computer interaction at the University of Maryland. "The question becomes, 'Which are innovations that may be more acceptable to people, and how might a manufacturer accelerate adoption?' "

Brian Fung writes for the Washington Post.