Inside Amazon’s amazing Prime Now two-hour

delivery operation.

MILWAUKEE, Wis. — Among the most popular items requested by Milwaukee-area customers of Amazon’s Prime Now — the online retail giant’s service that delivers orders at no charge in two hours and, for a fee, in one — are potato chips.

When you need a salty snack, minutes count.

“We really tailor the selection to things that people need in two hours,” Amazon spokeswoman Julie Law said Thursday at the company’s nine-month-old Prime Now hub on Milwaukee’s south side, a well-swept mini-warehouse stocking what Law said are “tens of thousands” of items in seemingly haphazard

As Christmas pressure bears down on last-minute shoppers, Amazon wants customers to know that its famously rapid delivery stands ready to help the procrastinators among us.

So the big retailer — $136 billion in sales last year — offered a peek inside its local Prime Now fulfillment center, lodged inside an all-but-faceless commercial building.

Prime Now is the rapid-delivery option for subscribers to Amazon’s $99-a-year Prime service. Prime, which offers free shipping, streaming video and music, and other benefits, is hugely popular and is helping Amazon reshape the retail landscape. A report last week from Morgan Stanley estimated that 50% of U.S. households have a Prime member.

Compared with the company’s regular fulfillment centers, such as the million-square-foot building in Kenosha, the Prime Now hubs are small. The Milwaukee hub covers 25,000 square feet — a bit more than twice the size of a typical Walgreens store.

The place is meticulously clean and rigorously organized. No cellphones allowed past the lobby. No rattling wheels on the carts of the “pickers” as they move down one-way aisles, gathering items from bins tagged with advanced barcodes that sync with handheld devices the employees tote.

The items often have surprising shelf mates. Amazon for the most part doesn’t assign products to designated areas. Rather, it uses what it calls a “random stow” system in which stuff gets placed pretty much anywhere it fits.

In one bin, rooster-red bottles of Sriracha sauce stand alongside a wireless router. Nearby, an Amazon Echo Plus smart speaker is next to gluten-free chocolate wafers. Stocked in another bin are Donut Shop coffee, a Lego set and an aluminum clipboard.

This method saves space. And with every item computer-tracked and identifiable by barcode, Amazon has found that it’s more efficient than stocking things in assigned spots, Law said.

“We’ve got 23 years of learning about logistics and technology,” she said.

Further, she said, the system enhances accuracy among pickers. If all the coffee, for example, were stored in one area, Law said, it would be easier to mistakenly select another brand when what you wanted was Donut Shop.

Computerized as the hub’s operation is, Amazon leaves it up to employees to decide where to stock items based on where they best fit. It might be that the bin with a couple copies of “Harry Potter and the Goblet of Fire” is just the spot for six jars of baked beans.

“The human brain is better at that than a machine,” Law said.

Gray metal shelving, seven tiers high with yellow plastic dividers separating individual cubbyholes, fills much of the hub. Several “high velocity pallets” near the front are stacked with such frequently ordered items as Brawny paper towels, Charmin toilet paper and Aquafina bottled water.

Also toward the front are a walk-in refrigerator and freezer, with several black parkas hanging nearby. Pickers are supposed to put on a jacket before entering a cooler, which typically is the last stop in filling a given order. No one wants melted ice cream.

Once assembled, orders go into brown paper bags and onto a “SLAM” line — it’s an Amazon acronym for “scan, label, apply, manifest” — that prepares them for dispatch. Contract drivers, using their own cars, make the deliveries.

Amazon says drivers receive $18 to $25 an hour and touts the work as a “be your own boss” opportunity. Reviews posted on job site Indeed.com are mixed, but lean positive. On Thursday morning in Milwaukee, a handful of drivers waited in the lobby for deliveries to be assigned.

Two-hour delivery is free (to Prime customers) with orders totaling $35 or more. Smaller orders are charged $4.99. One-hour delivery is available on any order for $7.99.

Prime Now delivers seven days a week here, 8 a.m. to 10 p.m. On Christmas Eve, it will deliver up to a minute before midnight.

The hub gets plenty of Christmas-related orders — things like ugly sweaters and Amazon Fire video streaming sticks — but the foundation of the Prime Now business is less exotic, with groceries and household supplies being the largest categories, Law said.

“Those are always going to be the most popular items,” she said, “because it’s just human need: You’re home, you run out of toothpaste and you don’t want to run to the store.”

And the biggest seller of all? Bananas. In fact, Law said, the humble, easily peeled fruit is the most popular item in every city where Prime Now operates — even chip-munching Milwaukee.