In The PR Masterclass, I dedicate a chapter on how to build and maintain an effective list of journalists. I quote a study that estimates that 1.7 billion irrelevant press release emails were sent in 2009 alone. And because journalists have better spam filtering tools than ever before, PR practitioners who send spam press releases will find that journalists they really ought to be contacting with another story will have blocked them.
Actually, the PR practitioner won’t find this, because they won’t know that it has happened. Their emails probably won’t bounce, just go automatically into Google Mail’s bin.