Listening to feedback is part of running a business and being a leader. Some of it can help you focus your efforts and improve your leadership or a specific product or service. But not all feedback is created equal. Listening to too many people, or certain types of people, can actually hurt you.

Dorie Clark, a marketing strategist who teaches at Duke University's Fuqua School of Business, writes in Harvard Business Review about when you should ignore other people's advice and comments.

"Feedback from the right people--who are informed, helpful, and have your best interests at heart--is invaluable. But when it comes to everyone else, the best thing we can do is learn to ignore them," Clark writes.

Clark, who just published her second book (Stand Out), says she received a flood of constructive criticism and feedback during her recent media push to promote her work. "Most of it is either useless or destructive," she writes. "And for the sake of my own sanity--and accomplishing the goals that are most important to me--I've generally decided to tune out other people's suggestions and advice."

But how do you differentiate good advice from bad advice? Below, check out Clark's suggestions on when to ignore feedback.

Ignore vague feedback.

Clark says that the first rule of thumb is to ignore vague feedback. Clark's first boss would send back her work with feedback, "Make it different!" While you need to listen to your fellow executives, investors, and board members, you should ignore feedback when it's so ill-defined.

Clark says when people share "maddeningly non-specific feedback," including criticism like "I didn't think it was as strong as it could have been" or "There was just something off," it's not worth your time. "If they can't tell you exactly what the issue is, it's not your job to figure it out (unless they sign your paycheck)," she writes.

Ignore critiques on things that work.

You should ignore feedback when the critique is about "exactly what you're going for." If you release a product for a niche audience and someone tells you "it's too niche-y" this should help you realize what you're doing is working. Clark says she got an email from a reader who was unsubscribing to her newsletter because she found the emails to be "overly familiar," which is Clark's goal.

"Clearly this woman wasn't a fan of my approach, and that's perfectly OK. It simply means she's not my target audience, and her unsubscribing--which would be easy to take as a rebuke or rejection--can instead be taken as feedback that my goal of being a different kind of business thinker is working," she writes.

Ignore individual opinions.

If your entire customer base tells you the same thing, you better listen. But if one customer dishes out a particularly negative critique, don't give it much weight. "But the opinion of one person, no matter how influential that person is, isn't always reliable," she writes. 

"It's quite possible that their feedback isn't about you at all; it could be the result of them having a bad day, or their own personal bias (you're an abstract expressionist and they only like figurative painters), or the fact that you remind them of their mother-in-law," she writes. "One person's opinion isn't a trend."

Ignore personal attacks.

Sometimes, people don't like you and sometimes they will tell you. When it comes to Internet-based feedback, you should realize that the cloak of anonymity, or pseudonymity, can give people the courage to say hurtful things. Just because they are targeted towards you doesn't mean you need to heed their criticism.

"It isn't that your facts are wrong, it's that you're stupid. It isn't that they disagree with your strategy, it's that you're ugly. (One Twitter user recently sniped about my haircut.) Is it possible there's a grain of solid critique inside their schoolyard rhetoric? Maybe," she writes. "But--per the policy of only listening to feedback when it comes from more than one person--you can safely ignore the overt haters. If they have a point, you'll hear it eventually from someone else, in a form that's more professional, respectful, and less damaging to your psyche."

Ignore feedback from unreliable sources.

You should listen to feedback from trusted peers and respected sources, but you should ignore criticism from suspect sources. "Everyone may have an opinion, but that doesn't mean it's useful. Just as, in the Internet era, it's easy to drown in information overload if you don't meter your intake, the same is true of feedback," she writes. "The best way to sort the wheat from the chaff is to decide in advance who you respect, and only choose to listen to those people. If your friend who's a speaking coach tells you how you can improve your stage presence, you may want to listen; a random audience member, not so much."