Amazon
The Treasure Truck will drive around the city several days a week, jam-packed with a single "highly desirable" product each day.
These items will either be heavily discounted or otherwise unique, including limited edition "Glassbaby" cups, two porterhouse 24-oz steaks for $20, or a knife set for 50% off.
Shoppers can see where the Treasure Truck is, what it's carrying each day, and pick a time and place to go find it, all through a new section in the company's app.
That's likely one of the motivations behind the launch for Amazon: Getting more people to download and log into the Amazon Shopping app.
It also gives the company a way to test out a new kind of local pick-up that could eventually work alongside its Prime Now, one-hour delivery service.
Treasure Truck will be Seattle-exclusive at launch (Amazon declined to comment on whether it planned to spread outside of its home city), and starts Saturday, June 27 with a $99 inflatable paddle-board that usually retails for $476.99.
"It's a truck, but it's got treasure!" the narrator in Amazon's promo video gushes, "It's like a pirate ship, but with wheels, and a horn!"
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.