There are policies in place saying that you definitely can't look at the data around which third party sellers are doing well, selling lots of stuff. But also there's no auditing in place to see if you check it or not. It's all a big data warehouse and you have access to it.
And hey, you've heard everyone else is looking at this data. You're just taking a quick look to get ideas do you don't get fired. What's the harm? You'll help the company do well and won't have to polish your resume.
[0] https://www.businessinsider.com/amazon-performance-review-6-...