Hi Demeter! Thanks for the kind words. Mark's course is available on Udemy if you want to check it out.

https://www.udemy.com/course/careermastery/?couponCode=LETSLEARNNOWPP

Mark is a big fan of targeting the company (or companies) you want to work at specifically and applying to a small (focused) number of jobs.

So I think I remember he finds cover letters useful -- since they'll be customized and appropriate for only applying to a few positions -- but he puts them as less important than LinkedIn, your resume, and your professional dossier.