After months of increased public criticism about its grueling labor practices, Amazon announced Tuesday that it would begin paying all US employees, including part-time, seasonal, and temporary workers, at least $15 an hour and all UK employees at least £9.50 (with higher wages in London) beginning November 1. The move will affect 250,000 US Amazon employees and 100,000 seasonal workers, according to the company.

In the same announcement, Amazon also said it will begin lobbying Congress to raise the federal minimum wage, which is currently $7.25. Jeff Bezos—the company’s CEO and the richest man in the world—said in a statement that Amazon “listened to its critics,” and “decided we want to lead.”

On its face, Amazon's decision to raise wages is unequivocally a good thing, with the power to positively impact the lives of hundreds of thousands of workers who were paid low wages even as their employer amassed enormous wealth. The pay increase also demonstrates the effectiveness of the Fight for $15 movement, a grassroots push formed in 2012 to increase pay and form unions in the retail and fast food industries.

"Amazon didn't pick $15 for no reason whatsoever but because of its symbolic importance," says Ben Zipperer, an economist at the Economic Policy Institute who studies low-wage labor markets. "Political pressure can actually change wages in our economy, which I think is a helpful reminder."

Amazon has also sustained months-long attacks from politicians like Bernie Sanders, who introduced a bill last month literally called the Stop BEZOS Act. The legislation is designed to force large employers to raise wages by taxing them when their workers need to rely on public benefits like food stamps.

Sanders’ initiative provoked a rare response from the typically shy Amazon, and the senator appeared pleased Tuesday when he learned his effort had seemingly worked. “Today, I want to give credit where credit is due. And I want to congratulate Mr. Bezos for doing exactly the right thing," Sanders said at a press conference this morning. Bezos later basked in the praise on Twitter.

Amazon is likely betting, however, that increasing pay will do more than just alleviate pressure from lawmakers and activists who want the retail giant to improve its working conditions. In the coming months, the company will need to attract 100,000 seasonal employees in the US and once again try to dominate the holiday shopping season. It has to accomplish those tasks in an extremely tight US labor market—the unemployment rate recently dipped below 4 percent—where few people are looking for jobs. Wage hikes like Amazon’s have historically occurred in similar economies.

"This isn't really anything new," says Sylvia A. Allegretto, a labor economist and the co-chair of the Center on Wage and Employment Dynamics at the University of California, Berkeley. "It typically happens around tight labor markets. Don't forget that Amazon needs a lot of workers coming in for the holiday season."

Making hiring matters worse for Amazon is the fact that it has faced a steady onslaught of bad press in recent months about its labor practices both in the US and beyond. One report published in April documented how some Amazon workers were forced to pee in water bottles to meet workplace demands, and another from July found some employees have suffered from workplace accidents that left them homeless.

Last week, Gizmodo also published excerpts from an internal video for Whole Foods managers that appears designed to train them to spot and squash labor organizing efforts. (It has previously been reported that employees of the Amazon-owned luxury grocery chain were planning to unionize.)