This will be entertaining
For those not in the US, this happens every single time a company announces they're expanding or not happy with their current situation. Atlanta is not a surprising choice...they spent most of the 90s vacuuming up corporate headquarters and back offices from around the country with lures of cheap taxes, free services and land as far as the eye can see. I imagine every municipality in Texas, North Carolina and other southern states is also competing heavily on a very similar platform.
What I'm not quite getting is whether Amazon is planning on formally splitting off AWS from retail and sending the retail part of the business off to Siberia somewhere while they compete head to head with Azure in Seattle, develop Alexa, etc. I wonder whether they're going to need smart people or just back office order processors...that will definitely determine where they put their headquarters. As an example, the financial company running my 401k is based in Boston, but all the drone work is done in Dallas.
The entertaining part will be seeing which municipality bent over the furthest backwards to attract the new HQ. I live in New York and we're constantly losing large employers who can just pick up and move because lower-cost locations will suspend taxes for decades, build them a headquarters for free, pay their electric and gas bills, reconfigure roads and zoning laws, and basically anything else they ask for. I imagine it's going to be somewhere in Georgia or Texas...cheap labor, nearly zero taxes for the well connected, and much more room to maneuver.