Be persistently polite and politely persistent

Be persistently polite: Your career is a multi-round game. Don't think of any transaction as one-off. Assume that everyone your interact with might be your boss or the decision maker at your customer some day. Treat them that way. This is perhaps too obvious to mention by itself in a blog post. Only worth noting as a pair to the inverted form:

Be politely persistent: Just because you emailed the hiring director/boss/acquaintance once with your request for an interview/permission/favor, don't assume that she is still thinking about it and just trying to reach a decision before getting back to you. Odds are, your email has been lost in the shuffle.

Maybe she meant to respond, and is still meaning to respond, but now your email is buried several hundred emails deep and she can't overcome the activation energy required to search for your email in order to get back to you.

Do both of you a favor - reach out again, politely. Forward your last email with a "Just wanted to follow up on my email from a week ago; when would be a good time to discuss?"

I can think of numerous examples where I've been helping a client fill an open position where a bit more persistence might have been a deciding factor. "Just wanted to follow up on my inquiry from a week ago. I remain very interested in the opportunity you are seeking to fill and would love to have a chance to discuss my qualifications..."

The worst that can happen is that you'll be told that you aren't in the running for the position.

Best case - you might be hired.

I know one VP of Sales who, after interviewing candidates for a sales role, doesn't hire anyone unless they attempt to follow up with him six times. In his industry, it takes on average six attempts to reach a customer before making a sale, and he isn't interested in hiring anyone who will give up on the fifth attempt.