Apple has launched new Limited Time Trade-In program for users that plans to buy new iPhones, and it will provide up to $100 extra credit. The devices that are eligible for the offer including the iPhone 6, 6 Plus, 6s, 6s Plus, iPhone 7, 7 Plus, and the 8, this comes after Apple had its four-day Black Friday promotion.
iPhone 6s, for example, in addition to its $100 original credit worth, you will also get an extra credit of $100, in total, Apple would give you 200 bucks when you trade-in this device, and then purchase new iPhones. However, it's unclear when the offer will stop, and it appears that this promotion only limit to the U.S..
For a limited time, you can get even more back when you upgrade to iPhone XR or iPhone XS and trade in your iPhone.
Apple has strict rules when it comes to trade-in: your iPhone must be turned on, it must be in good condition with the functional button, and it can't have a broken display. Though Apple offers recycling it, there is no compromise value for broken iPhones that don't open or broken buttons. iPhones with damaged displays get less trading value, you can go to your local Apple Store to trade-in as well.