In May, Gazelle hit its millionth customer, a major milestone for the silently scaling South Boston business. Since its start in 2006, the company has gone on to raise $46.4 million in funding from Venrock, Rockport Capital Partners, Physics Ventures and more for its tech device buying and reselling marketplace. The electronics reseller claims to have banked $100 million in revenue in 2013, and has been growing at around 150 percent year over year.

The user experience secret behind its widespread success? Thinking outside the box, or rather  – to make my admittedly bad pun even worse – inside it…

Consumer-facing product companies dish out thousands on perfecting their physical branding. The pretty, thoughtfully designed package in which the product is ultimately presented is an essential part of the initial user experience. So pretty, in fact, that hundreds of people have recorded the thrill of opening up their tech devices in “unboxing” videos. Take this one of Apple’s iPhone 5S, for example.

And while Gazelle works on a marketplace model, the firm has poured just as much thought and energy into its user experience, and the gadget shipping step, as traditional consumer product companies have put into their packaging.

When a user goes to a sell a used device – be it a smartphone, a tablet, a computer or an iPod – Gazelle first gives them a quote for the device. If the user opts for help on the shipping side, the company then sends him or her a box with which to send said gadget to the firm’s Louisville, Kentucky processing facility, which was opened in the summer of 2013. Once the bundle arrives safely and securely at Gazelle, it is assessed for any additional damages. The user gets paid back based on the model and condition of the phone, tablet or otherwise, and Gazelle puts it up for grabs on its e-commerce site.

So, we thought: What if we did an unboxing of Gazelle’s box – a box that, when it first reaches the consumer is, well, empty?

In the early days of the company, “we used to send people standard Post Service mailers, and just sort of shoved them out to people,” Alyssa Voorhis, the senior technical analyst of the customer box program at Gazelle, told BostInno.

Alyssa Voorhis

People would sometimes send in devices wrapped in diapers. “It was kind of concerning for the folks opening the boxes, actually,” joked Voorhis. Other times, Gazelle employees would open packages packed in pinecones as somewhat of a poor man’s bubblewrap. Popcorn was also a popular packing do-it-yourself alternative, despite the company’s suggestions.

“There was no way for them to suspend the device safely, and it went really, really badly sometimes,” explained Voorhis, adding users ran the risk of their gadgets arriving in even worse condition.

So, in early 2012, the Gazelle design team took the matter into their own hands, and began brainstorming creative solutions to their packaging puzzle.

Still, there were costs to consider. “We wanted to minimize size and weight of the box, and reduce our carbon footprint,” shared Voorhis. Ability to recycle the selected vessel was a must. Plus, it needed to be able to fit everything from a svelte iPhone 5S to a chunkier Samsung Galaxy.

Ultimately, the team went through months of “more than 100 iterations of different trials – a soft-package envelope, a bubble envelope – before ultimately deciding on the box,” said Voorhis.

The winning product is a pre-paid, Gazelle-branded box, which the company started using in earnest in fall of 2012. Customers can request a shipping box via the website, and two to five days later, the free box should arrive at their door. To keep things green, instructions and shipping addresses are printed on the box itself. The only extra piece is an orange sticker that’s used to seal the box when it’s ready to ship. As one would expect, the boxes come in varying sizes depending on the type of device you’re looking to resell to Gazelle.

The company sent us two pre-paid, Gazelle product shipping boxes – one smartphone-sized, the other designed for tablet – to play with. So, we naturally decided to do a little unboxing video of, ahem, the Gazelle product shipping box. Check out the video above, and let’s get meta.

Writer’s Note: Starting in 2013, Gazelle started having products mailed to its processing facility in Kentucky. The piece has been updated for clarification.