I'm addicted to Amazon's new 1-hour delivery service

Amazon has a new one-hour delivery service and it might bankrupt me.

The service, called Amazon Prime Now, was launched in New York City in December. Until that point, I shopped on Amazon only about five times a year.

But in the last six weeks, my husband and I have made an embarrassing number of orders through Amazon Prime Now.

It's cheap, easy, and insanely fast.

And here's the trick: you don't need to pay for one-hour delivery to get your items in an hour.

We made our first order in mid January after returning from a long, snowy walk with our dogs that left them drenched in black slush. Both dogs needed a bath and we were out of cleaning supplies.

My husband and I were too lazy cold to go back outside, so we decided to test Amazon's new service.

We downloaded the Amazon Prime Now app, which is the only way to place an order.

We discovered that one-hour delivery costs $7.99. After that, delivery is free.

It was 11 a.m. and we chose the option for free delivery between 12 p.m. and 2 p.m.

Our doorbell rang at 12 p.m. - exactly one hour from the time we ordered.

Over the next couple weeks, we made several orders for items that we definitely didn't need, but were unable to stop ourselves from purchasing because we're suckers for instant gratification.

Every time, we chose free delivery and got the orders within 65 minutes.

The service is available in Manhattan and parts of Brooklyn for customers who have Prime memberships, which cost $99 a year.

The company said it's planning to expand Amazon Prime Now to other cities this year, but hasn't revealed any further details.

So far we have purchased an electric blanket, groceries, board games, a space heater, cleaning supplies, and more.

The overall selection is smaller than Amazon.com, (i.e. seven electric blankets to choose from instead of 500) but we've been able to find everything we've needed to satisfy all our spontaneous cravings.

Amazon Prime Now is the latest addition to the burgeoning "on-demand economy," driven by startups such as Postmates and Wun Wun that immediately fulfill customer needs.

The car service Uber also recently unveiled its own delivery service, called "Rush," that uses bike messengers to deliver items in Manhattan.

The growth of the on-demand economy is putting new pressures on traditional retailers to offer services like in-store pickups and and fast shipping at no charge.

It's easy to see why. If there's no extra cost to get something I need delivered to my door within minutes, why would I step foot inside a store?

Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.