Among the thousands of people from Hebron, Kentucky to Kent, Washington who stood in line yesterday to speak with recruiters at Amazon’s fulfillment centers, their thinking was clear: Amazon is their ticket to a good-paying, stable job. The long lines came courtesy of a mass-hiring event dubbed Amazon Jobs Day, in which the ecommerce giant announced that it would be hiring for 50,000 jobs — 40,000 of which were full-time.

Many of the job seekers cited Amazon’s benefits package — which includes a 401(k) retirement plan, stock in the company, opportunities to pursue specialized training covered by Amazon, and the pay of more than $11.50 per hour — as their reasons for pursuing employment at Amazon.

Danny Aviles, one of the hundreds of people who waited in line on Tuesday to meet with recruiters at Amazon’s Kenosha, Wisconsin fulfillment center, told the Milwaukee Journal-Sentinel that he sees a job at Amazon as a “dream opportunity.” He said that he had been shuffling through a series of temporary jobs for nearly 10 years since his former employer, a nearby Chrysler plant, closed. “I’ve worked for four companies that closed their doors. I want to be somewhere I’m confident is going to stay,” Alice Goncher, one of the people who stopped by the Romeoville, Illinois, Jobs Day event, told the Chicago Tribune.

“A record-breaking 20,000 applications were received on this day alone, with thousands of job offers extended to candidates and more to come in the next few days,” Amazon human resources vice president John Olsen said in a statement. “We continue to process candidates at events across the country and expect that to continue over the coming days.”

As one of the most valuable companies in the world, Amazon won’t be shutting its doors anytime soon. But there’s no guarantee that the jobs at its fulfillment centers will be sticking around for everyone.

Open a new warehouse, and it won’t be long before someone asks when the jobs at the warehouse will be replaced by robots. Amazon uses warehouse robots made by Kiva, which it purchased in 2012. According to The Seattle Times, the number of Kiva robots Amazon uses in its fulfillment centers has increased by 15,000 each year since 2014. For now, Amazon is using its robots to supplement work done by humans. But with patents that include an aquatic storage facility and a combination flying warehouse-landing pad for drones, Amazon has plenty of ideas of what warehouses with little to no human staff could look like.

When Amazon opened its first slew of fulfillment centers in 1999, it chose sparsely populated areas with low tax rates or that offered Amazon generous incentive packages, like Fernley, Nevada and Coffeyville, Kansas. But as the ecommerce giant has grown and introduced same-day delivery, it’s been willing to open more of its fulfillment centers toward larger metropolitan areas that were previously too expensive to operate in.

Amazon moved the Fernley fulfillment center to Reno in 2014, allowing all employees to transfer if they desired. Amazon also closed the Coffeyville fulfillment center in 2015, turning down a reported $10 million incentive package. In 2016, Amazon opened a new fulfillment center in Edgerton, Kansas — nearly 150 miles closer to the Kansas City metropolitan area than Coffeyville. The list of Amazon fulfillment centers scheduled to open in 2017 includes many large population centers, like Miami and Houston.

Job seekers in places like Kenosha may see Amazon as the town’s next Chrysler. Amazon sees its fulfillment centers as the places that as of today, allow it to get products to the most customers as quickly as possible. When that changes, Amazon has plenty of other places to go.