I've been told that some sites won't cover a band/artist unless they have a PR rep, which I find to be pretty stupid. I couldn't possibly care less about shit like that. In fact, unless something about an email happens to pique my interest, the vast majority of PR email blasts that I receive go straight into my trash folder.
On the other hand, if you send me an obviously personal message, I will 100% check out your music. That doesn't mean I'll write about it—I really don't write about all that much, and most of what I buy and listen to are older releases or reissues. That being said, I'm still always on the lookout for cool new jams, so it's definitely worth a shot to hit me up!