For nonfiction, the author’s platform and expertise
This means how many followers do you have on social media. How many speaking engagements and workshops are you doing. Who are your clients and how many podcasts are you a guest on.
If you’re a journalist, we want to know who you are writing for or who you have written for. If you’ve written and published on this subject, we want to know who with, where and when.
When reading nonfiction queries I look at the idea and then I look at the author bio. If you don’t have a platform, I’m not likely to request more material.