Amazon completely changed the book selling and publishing industries when it opened the virtual doors of Amazon.com.

The company then expanded into selling all manner of consumer goods. And it’s the leading online retailer, and the world’s third largest retailer – with only Walmart and CVS ahead of it.

Amazon also pioneered the public cloud arena. And it’s the market leader in this product category.

Its recent purchase of Whole Foods has catapulted Amazon into a leading player in the grocery store space as well.

Amazon has also continued to innovate in eliminating the friction of customer buying.

Just a few clicks and you can buy just about anything your heart desires from Amazon.com. Returns are easy too – just print out a mailing label, affix it to your return package, and drop it off an area shipping location.

We’re all familiar with Amazon’s advances on product delivery as well. Amazon Prime allows us to get our orders in record time – as short as a day or two. Amazon has also been working on using drones for package delivery.

And just yesterday Amazon unveiled a new service through which delivery people can actually enter the homes of Amazon Prime members to drop off Amazon packages. The service, called Amazon Key, will be available in 37 cities and surrounding areas in the U.S. starting Nov. 8.

Amazon Key is enabled by the company’s own Cloud Cam along with compatible smart locks from Kwikset and Yale. The do-it-yourself kit started at $249.99.

“This state-of-the-art technology doesn’t simply replace a key with a digital passcode,” Amazon explains. “Each time a delivery driver requests access to a customer’s home, Amazon verifies that the correct driver is at the right address, at the intended time, through an encrypted authentication process. Once this process is successfully completed, Amazon Cloud Cam starts recording and the door is then unlocked. No access codes or keys are ever provided to delivery drivers.”