Apple's in-store trade-in values are among some of the lowest, convenience notwithstanding.
Apple will now offer you money for your old iPhones, kind of. Apple's money comes only in the form of store credit, and that store credit can be used only to purchase more iPhones. Apple is also only taking iPhones—there's no word on whether Apple will also accept iPad trade-ins somewhere down the line, to say nothing of products from other companies.
Last year, we looked at a few different hardware trade-in services to see what we could get for a 2011 MacBook Air and an iPhone 4. In light of Apple's new trade-in service, we'll be revisiting some of those sites to see what kind of money they'll give you for your used iPhones so we can stack them up against what Apple will be offering in-store (for a more detailed description of each service, we encourage you to read last year's article—not much has changed since then).
Because part of the allure of Apple's program is the convenience—you take your phone into the Apple Store, they determine its value on-site, and you walk out with a new phone—we'll be focusing on services that require very little user input to work. You might be able to get more for your hardware on eBay, Amazon, or Craigslist, but we'll be focusing on services that require a bit less effort from the seller. Everything here simply requires you to ship your phone in to the service so that they can evaluate its condition before they cut you a big fat check.