People who talk too much and think you have unlimited time to spend.
Having said that, I’m very sympathetic to job seekers. It’s not easy, and a certain amount of pushiness is required. I like folks who are determined, and it’s a good sign when they happen to know something about my studio—it appeals to my vanity.
Anyone who has plucked your name out of a list without having done any research is committing a grave, and common, mistake.