By Jim Donovan

By Jim Donovan

PHILADELPHIA (CBS) — Apple says it sold a record-busting 13 million devices during the first weekend of sales for the iPhone 6s and 6s Plus.  For those with a shiny new smartphone in-hand this week, it’s always worth a few key reminders to protect that device and to make the most of the old one.

From the very first devices sold in Sydney, to smiling shoppers in Hong Kong, to consumers who camped out on the streets of Chicago in the early hours of Friday morning.

Apple said Monday it sold more than 13 million 6s and 6s Plus iPhones in the first three days on the market, a new record for an opening weekend.

That also means millions of old smartphones, with nothing to do. In anticipation of upgrades, each of the major wireless carriers rolled out trade-in deals for customers. Apple has their own trade-in program too, as do a number of major retailers like Best Buy, Target and Walmart.

Just like purchasing a device, shopping around is crucial for getting the best price for a trade-in.

Prior to researching, take an honest assessment of a smartphone’s condition, and how much storage it has.

Unlocked phones, phones not tied to a specific carrier generally get more money on resale websites.

Before finally trading in that phone, be sure to back up data to the cloud and perform a factory reset.  With so much personal data stored there, it’s important to take as much caution with an old phone, as with the new.