Apple's online refurbished store is an open secret that allows people to buy like-new Apple products at a significant discount.

Now Apple is selling refurbished iPhones for the first time. Apple is offering a variety of refurbished iPhone 6s and iPhone 6s Plus models for about $100 less than full price, or about 15% off.

For example, Apple is selling a 16 GB iPhone 6S for $449 — $200 less than its original price in 2015, and $100 less than a new one costs today. You have some choice in color, but some color and storage combinations are not available.

Basically, when a product is returned to Apple, it fixes the problem, replaces the battery, then puts the guts and other components into a new casing and sells it. Refurbishing returned devices helps prevent waste and helps boost Apple's bottom line when it doesn't have to eat the cost of returns.

For example, when Apple swaps out your broken phone at the Apple Store, it's usually giving you a refurbished replacement. In most circumstances, these are just like new, except they come in a plain white box with an Apple logo.

Refurbished iPhones from Apple come with a 12-month warranty, just like a new phone. Apple writes:

"We test and certify all Apple refurbished products and include a 1-year warranty. All refurbished iPhone models also include a brand new battery and outer shell. Supply is limited and availability is guaranteed once we receive your full payment."

One warning: Geniuses working at Apple Stores have told Business Insider that some refurbished iPhones could have the issue called "touch disease," which could make your iPhone screen unresponsive to touch.

Source: Business Insider