Any examples of learnings from a survey that changed your business (for the better)?

When I ran my SaaS app Wordable, we would consistently use customer surveys to identify ways we could reduce churn, new channels we could test on marketing, etc.

I'm looking for some examples of surveys you've run that have helped improve your business in some way. Whether it's learnings that led to product improvements, new growth channels, new messaging, etc.

Looking for ideas around what questions to ask and what insights those questions led to. Appreciate the help.