It’s Amazon’s fifth annual Prime Day. Or days? It’s 48 hours this time. Customers are expected to spend more than $5 billion. That means millions of orders processed in giant warehouses, which Amazon calls fulfillment centers. This work is increasingly automated, but there are more than 100,000 human workers in its North American centers (because humans are more economical for some things, especially if they must work unceasingly).

Marketplace’s Jed Kim spoke with Emily Guendelsberger, a journalist who took a temporary job at an Amazon fulfillment center near Louisville, Kentucky, in 2015. Her new book, “On the Clock: What Low-Wage Work Did to Me and How It Drives America Insane,” describes that work, as well as several other low-wage jobs she tried.

At Amazon, she walked the equivalent of 16 miles a day through a giant warehouse. She said workers like her weren’t allowed to listen to music for safety reasons, but also because security might think they’d stolen the MP3 player. Guendelsberger first described her job as a “picker.” The following is an edited transcript her conversation with Kim.

Emily Guendelsberger: I would walk around [in] this huge warren of shelves pushing a cart with a scanner and a little bin to put items that were ordered in. I would follow the directions on my scanner, and I would go find whatever item they needed and put it in the bin. When the thing got full enough, I’d go put the bin on a conveyor belt, and I would start a new one.

Jed Kim: How closely were you monitored by technology while you were working there?

Guendelsberger: You carry around this scanner gun — it looks like something you’d see at the grocery — and it tells you what task you must do next. It starts counting down the seconds that you have left to do it while staying ahead of the rate that you’re supposed to be working at. It’s very stressful to have every second of your day timed out — you have this digital manager lurking behind you disapprovingly with a stopwatch for 11 hours every day. It’s difficult, physically and mentally, honestly. It’s very mentally stressful.

“I would just sing all day until I was hoarse just because it was something to do that wasn’t just operating like a robot.”

Emily Guendelsberger

Kim: What was the most difficult aspect of the work?

Guendelsberger: After my body had started adjusting better to the physical workload, the isolation and the monotony would have been what really got to me if I had been staying there in the long term. The mod where I worked, which is the shelving system, you really didn’t get close enough to other workers to have a conversation, like very much at all. So it got very lonely out there. My ice breaker for smoke breaks and lunch breaks was, “What do you do while you’re picking to keep yourself from going nuts?” And a lot of people sang. I was a singer. I actually started memorizing songs in my off hours so that I would be able to have a more interesting repertoire. I would just sing all day until I was hoarse just because it was something to do that wasn’t just operating like a robot.

Kim: What did this tell you about what things are like in the world today?

Guendelsberger: Look at some of the effects of chronic stress, physically and mentally. Physically, chronic stress will give you all of what people call the diseases of civilization, like heart disease and a defective immune system, obesity, that sort of thing. But I find it more interesting to see what chronic stress does to behavior, like inside your head, in that chronic stress makes you more likely to believe in conspiracy theories. It makes you more likely to be aggressive and irritable. It makes it more likely that you will be interested in a strongman leader. There was a study that came out I believe in 2017 on that one that I find fascinating in the context.

Kim: How did your co-workers feel about the job?

Guendelsberger: It depended. It was very rare to run into someone who’d been there for more than a year in my mod, even full-time workers. So take everything with a grain of salt, given that probably people haven’t been there that long. But a lot of people said that Amazon paid better than comparable warehouse work and certainly better than retail and fast food, which it did. And they also said that Amazon was much safer than other warehouse work that you could get. Amazon always had water running, it’s climate controlled and it’s indoors. While repetitive stress injuries are something that are not quite as quantifiable as being squished by a forklift, I would say that repetitive stress injuries might take Amazon back up to be a little more dangerous than it appears. But those are kind of a far way off from being able to quantify stuff like that.

Kim: It is Prime Day today. How has this experience affected the way you use Amazon, or do you use Amazon?

Guendelsberger: My husband does. I’ve had a lot of people ask me about this book, “Hey, should I pre-order it on Amazon, or is that not cool or whatever?” My opinion on that is that consumer choices will not make change in society. You can’t expect people to act against their own self-interest when so much of America — you can’t expect people to buy something that’s more expensive if they can get it for cheaper on Amazon. The only way to deal with this stuff is government action.

Related links: more insight from Jed Kim

Emily Guendelsberger’s book was released during Prime Day, something she said wasn’t planned. What is planned, though, are Prime Day public protests against Amazon. TechCrunch reported on several demonstrations happening around the world as Amazon workers protest the conditions and culture at their job sites. Many want a better pay and benefits, as well as full-time status instead of temporary. The biggest employee-led protest is happening in Minnesota, where many Muslim workers protested in March, demanding more time for prayer, as well as less hectic workloads during Ramadan, when many fast during the day. The piece quotes an Amazon spokesperson essentially saying, “Hey, we already pay better than most other major companies.”

This year on Prime Day(s) (remember, it’s 48 hours) Amazon is making a bigger push into the fashion market. CNBC reported on the deals the company is making with fashion influencers and designers. An interesting note: The company sells tens of billions of dollars in apparel and footwear each year. A lot of that comes not from high fashion lines, but from basics, like T-shirts and socks.

Amazon may be the place to buy pretty much anything, but it does have its roots in book sales. That’s why many independent booksellers are pushing Prime Day(s) as an occasion to visit your local indie. LitHub has a collection of Twitter snark on that topic. East City Bookshop in Washington, D.C., tweeted this: