Amazon made the announcements at its annual conference for sellers hosted in Seattle. Third-party sellers are the heartbeat of Amazon's dominant e-commerce business. Since about 2017, they've accounted for at least half of all goods sold on the site. In the second quarter of this year, that number swelled to 61%.

Dharmesh Mehta, Amazon's vice president of worldwide selling partner services, told CNBC in an interview that a growing number of merchants are using its AI services. More than 400,000 of Amazon's millions of third-party sellers have used its AI listing tool, up from 200,000 in June, he said.