What role does data analytics & user feedback play in improving landing page & product performance?

It plays a MAJOR role. It doesn't matter how great of a landing page or product you have if you're not meeting your user's expectations

Data analytics provides insights into user behaviour and engagement on the landing page, guiding optimizations for better user experience. User feedback offers qualitative insights, uncovering preferences and pain points to refine the landing page and enhance overall product performance. Both help in informed decision-making and continuous improvement. If you want to collect customer feedback and testimonials I would highly recommend Feedspace- https://www.feedspace.io/. It will help you to take your business to new heights.