In truth, there isn’t a single most common error that puts me off a query letter… It’s never about one thing in the letter. It’s about every facet of the query letter as a whole. And even then, if you put the same good query letter in front of 10 different agents, all 10 of them might have a different response. And some would ask for sample pages and the others wouldn’t.
- Kristin Nelson on what makes a successful (or unsuccessful) query letter.