Amazon, which currently runs primarily out of Seattle, is making serious progress in its search for a city to host its second headquarters.

Hundreds of cities from across America made their interest in HQ2 known, but according to CNBC, we’re now witnessing a shift. For the 20 cities that remain in the hunt for HQ2, Amazon wants privacy—not publicity. The remaining stages of the cities’ bidding war will take place behind closed doors. 

There’s a lot at stake in this fight. It’s estimated that Amazon’s new facility will be worth around $5 billion and bring 50,000 new jobs to whatever city is fortunate enough to host it. Secondarily, landing HQ2 is expected to bring billions of dollars in additional investment to the surrounding community as the chosen city grows.

“It’s a very secretive process,” Miami mayor Francis Suarez told CNBC. “We’re obviously bound by confidentiality.”

Philadelphia mayor Jim Kenney added that for the cities still in the hunt for the Amazon project, there’s no incentive to tip their hand about what sales pitch they’ll make.

“If I were to lay out out now what we’ll offer, it would be criticized and looked at, and determined whether it’s good or bad,” Kenney said.

Quietly, though, the final 20 cities have begun to make their cases behind the scenes. The cities have offered tempting financial incentivesaround $7 billion’s worth from Newark and $5 billion from Montgomery County, Marylandas well as marketed their financial bona fides. Dallas, for example, has sold itself as the fastest-growing city in America as well as a titan of job creation.

It remains to be seen how the HQ2 selection process will play out from here. Amazon’s next announcement on the 20 finalists might come this spring, or it might take a year or more; it’s also unclear how many more stages remain. The corporation may opt to cut the field of 20 to an even smaller group of finalists, or it may be announcing a winner soon.