For a limited time only, Apple will give you up to $100 extra when you trade in your old iPhone and swap it for an or iPhone XR. Potential customers who are considering the latest iPhones should consider this promotion for Apple's trade-in program, known as GiveBack, as an avenue to recycle their old devices while saving on a new one.
As always though, there are caveats. The money comes in the form of an Apple Store Gift Card, and it only applies to a handful of iPhone models: the / , the iPhone 6S/ , the /7 Plus and the iPhone 8 (notice the and iPhone 8 Plus are excluded).
Also, depending on the model, you might not actually get $100. For example, an iPhone 8 will get you $25 of extra credit on top of its trade-in value, while the iPhone 6S will fetch you that full $100.
In addition, the trade-in value you'll get for the XS or XR varies on the condition of your phone. As a reference, Apple has a list of how much you can expect (the iPhone 6 caps at $75, while the iPhone 8 is worth $275), but be prepared to receive less than that if your phone is in less-than-optimal shape.