I have come across an excellent article on Referral Marketing:
There are three main reasons why a solid referral marketing strategy can be so powerful.
1. People feel more comfortable when a product or service is recommended by someone they know and trust. This is especially true if the product or service is expensive.
2. Referred customers are typically less price sensitive. A prospect that comes to you via a referral has already been told about the quality of your service. You’ll find that most referrals can be sold at full price because they’ve been presold on your trust and credibility.
3. A good referral marketing system can quickly multiply, giving you plenty of interested prospects. This will allow you to choose who YOU want to work with instead of having to take everything that comes your way. You’ll be able to focus on high-quality customers that are highly profitable for your business.