Getting full value for a trade-in on a smartphone is definitely more complex than with trading in a car, he said.
"Nothing in the mobile world is simple and trading in a smartphone is definitely complicated," Hold said. "There's no Kelley Blue Book for standard pricing and how valuable your phone will be. Some people will shop around for the best trade-in deal and others will take the first deal."
Smart carriers will realize the need to quickly react when their trade-in values are leading to lost customers, he predicted. The terms of the new loyalty programs are intended to slow down the urge to jump to another carrier.
"Trade-ins are very concerning for carriers, and it's added a whole new metric," Hold said. "Our older flip phones had almost no value, but now we are all starting to realize smartphones have a lot of value."
NPD found the average price for a trade-in of an iPhone 4S 16 GB with AT&T was $216 in July, with Best Buy and RadioShack offering the least at $150, with Amazon the most at $275. The prices listed by the four major carriers ranged from $155 to $225, while Nokia, Samsung and HTC all offered above-average trade-in values for the iPhone 4S as long as the new device was one of theirs.
NPD also found the average price for the same 16GB iPhone 4S on Verizon was $165 in July, while a Nokia Lumia 900 on AT&T got an average trade-in of $56 and a Samsung Galaxy S III 16 GB on AT&T got $158 and on Verizon got $155.
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