The e-commerce and cloud giant said Thursday that it was beginning a search for a site for “HQ2,” as it is currently calling the future development. It expects to spend more than $5 billion building the facilities.

Amazon (AMZN) said HQ2 would employ as many as 50,000 people in “high-paying” roles—the firm has more than 40,000 people working at its Seattle HQ. With that, and a somewhat vaguer promise of “tens of thousands of additional jobs and tens of billions of dollars in additional investment in the surrounding community,” it invited city and regional authorities across the continent to submit proposals to have Amazon locate HQ2 on their turf.

“We expect HQ2 to be a full equal to our Seattle headquarters,” Amazon CEO Jeff Bezos said in the statement. The company claims that its original headquarters put $38 billion into Seattle’s economy between 2010 and 2016.

So, which kinds of cities should apply? Amazon said it would prefer a “development-prepped” site in a metropolitan area with over a million inhabitants. The company is stressing that this won’t be a satellite office, but a complete headquarters with new teams and new executives.

The company said senior executives could choose to locate their teams in one or both of the two headquarters, and employees working in “HQ1” would get the chance to move to the second city, if they prefer.

This article was updated to note that Amazon’s Seattle HQ has over 40,000 workers, not 20,000 (an incorrect figure derived from Amazon’s corporate website).