iPhone trade-in is very popular and the reason is the high resale prices iOS (and Apple) products fetch. We generally see heavy trade in programs from big box retailers like Best Buy and Walmart and this gets more intensive as a new iPhone launch rumor springs up. Best Buy and Walmart were offering up to $225 for an iPhone 4S towards an iPhone 5 purchase, just a few days back. And though the trade-in programs have become increasingly popular recently thanks to more tech savvy consumers, these heavy trade-in offers are due to the imminent launch of a new iPhone on Sep 10th.
9to5mac reports than Apple will start offering iPhone trade-in program as early as next month, meaning this could be in a move to further motivate the current iPhone 4/4S/5 owners to upgrade to the new iPhone. There have been previous reports of Apple getting into this trade-in program and it makes sense for Apple to think that this will benifit them. Though selling your old iPhones to private parties on Craigslist or eBay and trading them in on online sites like, Gazelle and Glyde might fetch you more money for the old iPhones, the comfort and ease of doing this right in the Apple store along with the purchase of a new iPhone might be more alluring than we can imagine.