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Sean Scott is almost poetic when describing his intense interest in sidewalks.

"Each sidewalk is like a snowflake," Scott, who's soft-spoken with a friendly smile, told me with a bit of excitement in his eyes. "Because the textures are different, the way they're laid out is different, what we see on the sidewalk is different."

Scott, vice president of the Amazon Scout program, is particularly curious about the drab and overlooked sidewalk because that's the workspace of his Scout delivery robots. The e-commerce giant in January introduced these machines, which look like blue coolers on six wheels and can autonomously navigate suburban environments to bring packages to customers' homes. The company is already using them to deliver orders in Snohomish County, Washington, just north of Amazon's Seattle headquarters.

While Amazon has been mostly mum about Scout so far, Scott offered a more in-depth look at the robot during an interview last week at the company's re:MARS robotics and space conference in Las Vegas. Just across from him in our conference room sat one of these robots, powered off but appearing at-the-ready for its next assignment.

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"Customers have really welcomed Amazon Scout," Scott said. "They find the device really cute."

The bots are another effort by Amazon to add more technology and automation into its delivery infrastructure. It already uses hundreds of thousands of robots in its warehouses to store and move around shelves of products. It's also been developing drones to get packages to customers in less than 30 minutes. All this work should help Amazon in its costly push to transition its Prime two-day shipping program to one day, a plan it announced in April and is already rolling out.

Amazon isn't alone in its delivery robot work. Google, Workhorse and others are developing delivery drones, while Postmates and the startup Starship are working on sidewalk delivery bots.

But as robots have gotten more sophisticated, many people have raised concerns that these machines could replace a lot of human workers, such as autonomous trucks and taxis taking away thousands of professional drivers' jobs. A Brookings Institution study from January found 25% of US jobs, including food preparation and office administration, are already at high risk of becoming automated.

It's also hard to know how people outside of the Snohomish test area will react to having these camera-filled bots rolling down their streets.

"History has shown us that we never know how customers are going to react to anything until they experience it," said Brendan Witcher, a Forrester analyst. "The other thing history has shown us is some people will bristle and others will be delighted."

It will be up to Amazon, he added, to communicate and be transparent with residents to show them why such robots should be a part of their lives.

Scott said Amazon isn't developing Scout to take away workers' jobs but instead to improve and grow the company's delivery infrastructure. "We think it will make delivery drivers more efficient," helping them deliver more packages, he said.

Plus, Amazon's leaders have often mentioned that even as the company continues to find new ways to automate tasks, it also continues to hire rapidly as demand from customers grows.

Amazon on Friday lost its contract with FedEx Express, a sign of growing friction with its shipping partners as Amazon keeps developing its own delivery infrastructure. If more turmoil like that happens with UPS or the US Postal Service, Amazon will need all the help it can get -- from humans and robots -- to make sure it delivers its packages on time.

Teaching Scout to roll

Today, the Scouts are loaded up in vans and brought to neighborhoods where they make their deliveries. To ensure the Scouts are working properly, each robot is assigned an Amazon worker -- folks Scott called "ambassadors" -- who walks with the bots during their deliveries and removes the packages stowed away in their bellies. The Scout program started with six robots, but Scott didn't say how many robots are currently in use, or when and where the program will be expanded.

The idea is to eventually pair the Scouts with delivery drivers and let the robots operate more on their own, but the details are still being worked out, Scott said.

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For instance, there's no way to get packages out of a Scout now without a person coming up to it, pulling open its lid on top and taking out its payload. Scott said one idea could be to have Scouts wait for a while for customers to come home.

Also, the Scout has magnetic locks in its lid to keep its top closed while it's driving and to protect its packages from theft. It's possible a resident could use the Amazon app in the future to unlock the bot and get her package once she comes home.

To train Scouts on how to navigate around Snohomish, Amazon created bicycle trailers that were equipped with the same camera arrays as the robots. Riders would go around in neighborhoods capturing every detail of the sidewalks, streets, gutters and even the weeds.

Then, Amazon created virtual worlds that were nearly identical to the streets the Scouts would be driving on and trained the robots over and over again using these digital doubles. That way, when the Scouts were ready to go out into the real world, they would be far more prepared for what they were about to experience.

As the Scouts learn more about the world, they can be trained on less information to understand the way around new neighborhoods, allowing Amazon to quickly spread out more Scouts, Scott said.

To see where to go, Scouts are equipped with GPS, radar and front- and rear-facing cameras. Scott showed me a video of a Scout in action on the street, slowing rolling along the sidewalk and carefully stopping when a neighborhood cat jumped in front of it.

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The current version is being developed for suburban deliveries, but there's a possibility future Scout robots will be able to function in a city or rural areas.

While the Scouts remain a curiosity now, Scott said the bots were intentionally built to look cute, friendly and most importantly unassuming. Yes, the bots have a bright blue color emblazoned with the Prime logo on either side, as well as bright flashing lights, which are needed for when Scouts cross the street. Plus, when you open a Scout's lid, it's painted bright white and orange inside, offering a pleasing contrast to the blue exterior and giving the feel of opening a present.

Otherwise, Scouts were built so they would fade into the background and fit seamlessly in a suburban setting.

"That's exactly what we want," Scott said. "It's designed for boring."

Originally June 10, 5 a.m. PT.

Update, 9:50 a.m. PT: Adds more details about the Scout.