Small courtesies can lead to big sales. We live in a fast-paced, often impersonal era, but you can give yourself an advantage over your competitors with extraordinary service.

Several years ago, my husband and I decided to install an alarm system in our home. I interviewed three reputable companies. My decision to go with one company over another was largely based on my interaction with their sales representative, Edward.

It wasn’t one particular thing. Instead, it was a combination of many small, important factors. Edward quickly responded to my call, presented himself in a professional manner, shook my hand, intelligently answered my questions and looked me in the eye. He made me feel as if I were his only customer. This level of service used to be customary. Now, it’s a rarity.

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It’s much easier to retain current clients than it is to find new business. A dissatisfied customer can cost your business more than revenue — it can damage your reputation.

The following are simple yet powerful business principles that will help you win relationships and earn repeat business.

1. Keep your word. Your credibility is dependent on your ability to keep your promises. It’s important to be upfront with your customers. If you can’t complete a task on time, notify everyone involved in the project immediately. Keep employees and partners informed of client requests or changes to the project’s scope. If you forewarn a client of a potential roadblock, he will be much more likely to be forgiving. No one likes a surprise, especially the day a project is due to be completed. Simply put, under-promise and over-deliver.

2. Be honest. Be truthful in every aspect of your business. Your credibility can be severely damaged if you intentionally lie, misstate or misrepresent yourself or your products and services. Clients in highly competitive industries, especially those whose product development requires a long lead time, require your discretion. Never share confidential information and betray someone’s trust. Instead, foster a reputation for honesty with customers.

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3. Show up on time. Punctuality is a reflection of your overall organization. If you are consistently late, your clients may begin to wonder if you’re the right person for the job. Aim to arrive early. It gives you time to use the restroom, compose yourself and check in with the receptionist before an important meeting. Give yourself extra time to account for traffic delays, parking challenges or unfavorable weather. If you are going to be late, call ahead and let your client know when you expect to arrive. Be generous with your estimate; you don’t want to have to call again.

4. Acknowledge mistakes. Everyone makes mistakes. Generally, clients will be flexible if you quickly acknowledge the error, apologize and work to rectify the situation. Never try to cover up or ignore your or your company’s involvement in the problem. Don’t make excuses or blame others. Instead, take responsibility. Focus on the solution, learn from the mistake and move forward.

5. Handle conflicts gracefully. Disagreements and personality conflicts are part of doing business. If a client, partner or employee tests your patience, questions your authority or criticizes your work, don’t react with hostility. Strong leaders remain calm in even the most trying circumstances. Even if you are boiling inside, don’t let others see it. Maintain a calm disposition and stay on topic. If you must concede, do so with grace.

6. Don’t burn bridges. Entrepreneurs, for the most part, are extremely passionate individuals. Your business is your baby. You’ve dedicated years of your life to build a successful, thriving organization. When you or your business is threatened, your first reaction may be an emotional one. As Warren Buffett once said, “It takes twenty years to build a reputation and five minutes to ruin it.” If you need a few minutes to cool down, walk away and return to the conversation or email later. You never know what the future holds. Today’s foe could be tomorrow’s ally.

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