Apple will discount your iPhone payment plan if you trade in an old phone
It's part a new program at Apple Stores called "Trade Up With Installments," which started on Thursday, according to USA Today.
Previously, Apple Stores took trade-ins for credit towards a new phone, and iPhones could be purchased on installment plans, but there was no way to combine the two.
Apple handles the installment plan as an interest-free loan.
Apple is targeting the program mainly at users who are still hanging onto older iPhones, going back to the iPhone 4. But Apple will even give up to $300 in trade-in value for certain Android phones as well.
Here's how it works: Currently, customers can pay $32.41 on a monthly basis for an iPhone 6S. If you trade in an iPhone 4 or 4S in good condition, Apple will give you a trade-in value of about $100, so your monthly payment will only be $28.25 per month.
CNET has a good breakdown of what you'll pay based on what phone you're upgrading from.
Recently, some analysts have raised the possibility that Apple has passed "peak iPhone," and the company has advised that iPhone sales might fall year-over-year for the first time ever this quarter. Trade Up With Installments is a relatively straightforward way to get a few more people to decide to upgrade to the most recent iPhone.