It doesn't require any actual experience as a scrum master, but it does provide some very useful information on different delivery models, and it is still something you can put on your resume indicating you have knowledge in agile lifecycles which is sought by many employers today. Saving Changes...
DASM is an entry-level agile-focused certification so can't really be compared with an experience-based credential like the PMP. However, if you were deciding between PSM I, CSM or DASM, I'd suggest DASM as it provides exposure to a much broader set of practices which are applicable to many contexts and not just technology projects.