As Amazon continued to send more and more shipments, it became obvious it needed new ways to package them.

It developed a series of new packing strategies, including creating envelopes for smaller shipments and a system for items to ship in their original packaging.

This cuts down waste and reduces the size of shipments.

Amazon delivered more than a billion packages for the first time in 2016, and it's on track to ship even more in 2017, so it makes sense that the company is striving to make its boxes more efficient.

Amazon had been criticized on social media for years for its practice of packing tiny items in big boxes.

The company has introduced a few initiatives to mitigate the annoyance and environmental impact of packing numerous boxes in one.

Frequent Amazon shoppers may have noticed some smaller items being packed in bubble mailing envelopes, which the company started using this year, according to the Wall Street Journal. A machine in a warehouse can create custom sizes, and now, half of the items that would have gone into the smallest-sized box are shipped in envelopes instead.

Amazon has also improved its shipment algorithms, the Journal reported. It uses machine learning, which can do things like scan reviews and customer feedback to make choices about which items can be packaged together - and which size box they can be packed in.

The third peg of the stool is Amazon's "frustration-free packaging," which means that some items can be shipped in their original boxes. This reduces waste and eliminates the need for items to be shipped in a larger box.

Importantly, packages used to ship online orders don't need to be eye-catching.

"Almost universally, packaging designed for brick and mortar is oversized with expensive and redundant shipping features," Brent Nelson, a customer-packaging executive at Amazon, told the Journal.