Customer loyalty is the key to profitability. The reason is simple. It costs more–geometrically more–to acquire a new customer than to keep a current one.

Without customer loyalty, customers leave. Then you can end up sacrificing as much as a third of your sales year just to get your numbers back to where they were the previous year. Ouch.

With that in mind, did you ever wonder how top salespeople keep their customers so loyal? It's not because they have great products or they're good at schmoozing. The secret to customer loyalty lies in putting the interests of the customer ahead of your own. It's really that simple.

Here are eight rules for making this happen:

1. Have a sales philosophy that emphasizes relationship building.

2. Define a unique niche and become the customer's expert on it.

3. Help the customer build the customer's own business.

4. Translate what you offer into the customer's business results.

5. Value the relationship more than making your quota.

6. Think end-of-time friendships, not end-of-month totals.

7. Achieve a perfect job of delivering what you've promised.

8. Provide absolutely impeccable service after the sale.

The above is based on a conversation I had with amazing sales mega-guru Jeff Gitomer. I love his stuff and I featured some of his ideas in my recently published book.