Amazon (NASDAQ: AMZN) announced that it will invest $660 million over the next year to increase compensation for its delivery service partners (DSPs). Amazon relies primarily on DSPs for package delivery, and these small businesses employ drivers and determine their compensation.

With this investment, Amazon expects the average hourly wage for drivers nationwide to increase by at least $1.50 to more than $22 per hour, depending on the region. This increase is up about 7% from last year.

The funds are part of Amazon's additional $2.1 billion investment in the DSP program, bringing the company's total investment over the past six years to $12.3 billion.

In addition, Amazon will soon launch an app designed for DSP drivers that allows them to withdraw up to 50% of their earned compensation in advance before payday.

By the end of this year, Amazon plans to use artificial intelligence technology to identify red flags on 200 million roads around the world and provide 18 million safety tips to drivers.

The investment comes days after a National Labor Relations Board prosecutor ruled that Amazon should share liability with a contractor for allegedly taking illegal steps to prevent delivery drivers in the Atlanta area from forming a union.

In addition, another NLRB regional director in Los Angeles ruled that Amazon should be considered a "joint employer" of another contractor's employees and therefore required to negotiate with the union.

In response, Amazon previously said that its control over contractor drivers was not enough to constitute a joint employer.