Amazon.com’s purchase of Whole Foods prompted lots of talk that it has become a brick and mortar retailer. But Amazon already had a huge amount of property in North America, thanks to its expansion in e-commerce and cloud computing. And its properties are increasingly crowded with workers.

Amazon’s North American properties more than tripled to 112 million square feet between 2011 and 2016, according to filings with the Securities and Exchange Commission. The vast majority of that was in “fulfilment centers” and data centers in North America, which quadrupled to 99 million square feet in 2016 from 26 million in 2011. (See chart above.) Whole Foods had 17.8 million square feet of retail space as of September 2016, by comparison.