iPhone upgraders leave nearly $13.5B in old hardware to collect dust

The results of a survey published on Wednesday show U.S. consumers who hold on to last-generation iPhones after upgrading or moving on to another smartphone have amassed some $13.4 billion in mothballed hardware.

According to research group OnePoll's "Mobile Mountain Study," conducted for resale website SellCell.com, iPhone owners are leaving a collective pile of unused legacy hardware on the table estimated to be worth $13.4 billion on the resale market, reports MarketWatch. That number has grown from the year-ago period, which saw about $9 billion worth of iPhones stashed away.

Looking at the bigger picture, the percentage of owners who keep smartphones rather than selling them has decreased from last year, dropping to 50 percent from 55 percent one year earlier. The overall trade-in value of mothballed phones is up to $47 billion, a significant jump from $34 billion a year ago.

As for what people do with their old phones, 20 percent said they gift them to family and friends, 12 percent donate to charity and 9 percent simply throw them away. According to the poll, only 18 percent of users showed concern over security issues related to reselling or giving away handsets, down from 23 percent last year.

As to why Americans "hoard" old phones instead of selling or gifting, the survey found 40 percent keep legacy devices as spares, 36 percent "don't know what else to do with them" and 17 percent of respondents were just "too lazy."

While SellCell.com obviously has skin in the game when it comes to smartphone resales, the results from OnePoll are interesting considering that Apple instituted an in-store trade-in system last year to boost sales of new handsets.

According to SellCell.com, many consumers don't know about trade-in services and thus leave massive amounts of money sitting in sock drawers and shoeboxes across the nation.

A number of dedicated online services, like Gazelle, have popped up to take advantage of the second-hand smartphone market. Even big-box retailer Walmart and Internet sales giant Amazon are getting in on the action with sometimes generous offers on years-old equipment. These big-name companies usually take advantage of the time period surrounding new product releases to build their supplies or push promotions. AppleInsider tracks trade-in values daily in its Trade-in Cash Payout Guide: