YSK: If you're job hunting, despite the widespread myth that cover letters don't matter and are ignored - companies absolutely do read them and some will bin your application if you haven't at least gone to the effort of submitting one.
from /r/YouShouldKnow
YSK：如果你在找工作，尽管普遍认为求职信并不重要，而且会被忽视，但公司绝对会阅读求职信，如果你至少没有努力提交求职信，有些公司会放弃你的申请。