Surveys
Online surveys are commonly used by marketers, product managers, strategists, and others to gather feedback. There is a big chance that you have already been involved in one of them yourself before, but, most of the time, they are poorly executed.
Surveys are increasingly becoming a more accepted tool for UX practitioners. And for using this type of method, the cost is really low, even free in most cases, because we have Google Forms and other software that is free to use and no effort to learn them is required.
Creating a great survey is like designing a great user experience. They can be a waste of time and money if the audience, or the user, is not at the center of the process. Designing for your user leads to the gathering of more useful and reliable information.