eBay is testing a new same-day shipping service called eBay Now in San Francisco. Presumably, if successful, it will expand to more areas.

Merchants in the test group (which includes Postmates, TaskRabbit and Uber) can reportedly offer the service to customers for $5.

Owen Thomas at Business Insider has a step-by-step look at how it works, after making a purchase and accepting a delivery. According to Thomas, the service functions as an “on-demand delivery service,” which “picks up goods from local stores,” and delivers them to your door in about in about an hour. The couriers, he says, call themselves “shoppers”.

A really good point is brought up in that step-by-step slideshow: “The hour-long delivery window makes a lot of impulse buys possible.”

The whole thing brings something of an instant-gratification factor to e-commerce. Historically, when people have shopped online, they’ve had to wait to get their products. This really does bring more of an offline shopping element to the table. Imagine if they added a mobile fitting room service, allowing you to try on clothes before purchasing.

According to TechCrunch, users can use the eBay Now option with any store on the company’s Milo platform.

Users can simply pay with their credit cards or PayPal accounts.

You can sign up for the beta here, if you live in the area.