Most salespeople concentrate on learning how to make new sales. But they also need to know some important common ways to avoid killing sales.

Here are some mind-sets (paradigms) that can keep you from developing the long-term, profitable relationships you desire.

1. “I know more than my customers.” Because you are an expert on what you sell, you may think you’re more knowledgeable than your customers. Caution: Although you’d never intentionally talk down to your customer, you may sound condescending. Without realizing it, you may make customers feel uncomfortable – not O.K. – and drive them away, by talking down or over their heads.

2. “My customers know more than I do.” Do you assume that customers know a lot more than you do? In fact, they think they know more, but may be very uneasy about their problems and are hoping you’ll probe with questions to help them discover the real “pains.”

3. “This account is solid.” Do you believe customers automatically turn to you? If you’ve served them well, it’s easy to expect repeat business. Caution: No account is ever safe. Don’t let competitors in the door because you take customers for granted. Your best customer is your competitors best prospect.

4. “That customer is small change.” Do you categorize customers by sales volume and not by potential? Caution: They sense how important they are to you. Don’t treat them as second class citizens.

5. “I know my customers have confidence in me.” Just because they order from you doesn’t mean they have full confidence in you. Caution: If you assume they do, you stop trying to earn their confidence. You’ll do the same level of business with them forever, because you’re not working to develop the account.

These mind-sets stem from how you perceive customers and how they interpret your actions. Being aware of how customers see you can help maximize your sales.