Verizon is still taking trade-ins, regardless of carrier they say. Heck, they even go on to mention that they even accept AT&T's iPhone, which they've been doing for quite some time now. Remember when we compared their trade-in values to just selling something off on Ebay?
Well, that 16GB iPhone 4 will still fetch you $212. That's a far cry from what you'd get selling it off yourself. Heck, there are plenty of ways to get rid of your old iPhone if you must.
Well, maybe convenience also comes at a price. Though it's definitely not an enticing offer.