CNN Business  — 

Apple said Wednesday it will slash the fees it charges app developers from 30% to 15% if the developer made less than $1 million in the prior year.

The change for small businesses will go into effect on Jan. 1, Apple (AAPL) said, while apps that earn more than $1 million a year will continue to be covered by Apple (AAPL)’s existing fee structure, which charges 30%.

It was not immediately clear how many small app developers will be affected by the change; Apple’s announcement said only that the update will benefit “the vast majority of developers” on the App Store. Apple declined to elaborate.

More than 97% of iOS app publishers tracked by app metrics firm Sensor Tower generate less than $1 million a year in app-based consumer spending. Those developers’ economic activity accounted for an estimated 5% of the iOS App Store’s total revenues in 2019, Sensor Tower told CNN Business.

Apple’s App Store fees have increasingly come under scrutiny as lawmakers and regulators have zeroed in on Apple’s dominance over iOS.

Leading members of the House Judiciary Committee found in a landmark report this fall that Apple, along with Amazon, Facebook and Google, enjoy “monopoly power” and have wielded that power in anti-competitive ways.

In addition to app store fees, Apple’s developer policies have been criticized as helping to preserve the company’s dominance. This summer, Epic Games, the maker of the hit online game Fortnite, filed an antitrust lawsuit against Apple that could reshape how app stores work in the United States. This week, Epic expanded its litigation against Apple to Australia.

Apple has previously said that its fee structure reflects common practice across the digital services industry – this year, it commissioned a report by the Analysis Group, a consulting firm, affirming that claim. Apple has also said its policies are meant to enhance consumer security.

Asked whether the recent antitrust scrutiny may have played a role in Wednesday’s announcement, an Apple spokesman did not provide a direct answer but told CNN Business that it has only ever lowered the fees developers must pay.

Advocates of aggressive antitrust action hailed Wednesday’s decision as an outgrowth of the public pressure.

“Just the specter of antitrust action creates market structure change,” tweeted Matt Stoller, director of research at the American Economic Liberties Project, citing the House investigation and the Epic litigation.