Last week The Census Bureau of the Department of Commerce reported 2016 US e-commerce results. Sales have grown by $53.16 billion in a year.

We wanted to look at how much of that was thanks to Amazon, to get a sense of perspective on the importance of this Seattle-based marketplace.

In 2016 Amazon’s net sales in North America were $79.78 billion, up from $63.72 billion the year before. Thus they’ve grown by $16.06 billion. However, Amazon doesn’t report gross merchandise volume (GMV) number, so this figure only measures Amazon’s own sales. But since roughly 50% of units sold on Amazon are from marketplace sellers, we are estimating that marketplace sellers generated $60-$80 billion in sales last year.

By plugging all these numbers into a formula we get that:

55% of US e-commerce growth was thanks to Amazon

We are estimating it to be anywhere from 50 to 60%, so the 55% is right in the middle.

Following this logic Amazon now contributes at least 40% of total US e-commerce sales. Amazon is growing 20%+ every quarter, compared to the 14% US e-commerce growth so Amazon’s share will continue to rise.

This is important to illustrate just how big is Amazon. For anyone unfamiliar with Amazon’s earnings and US e-commerce size, it might appear that Amazon is a pretty big site, but the market has many more players. That is true, there are many players trying to compete with Amazon, but as far as 2016 was concerned - Amazon dominated.

This is great news for marketplace sellers - those estimated $60-$80 billion in sales were divided up by hundreds of thousands of sellers. That number will rise 20% or more in 2017, creating more than $10 billion in new selling opportunities.