Nothing builds new business more reliably than gaining referrals from existing customers

. The power of the customer's voice through case studies, referrals, and testimonials, .. ideally shared by the customer is very likely to succeed and can deliver a stronger impact than other campaigns and carries virtually no incremental costs. What it does require is a commitment to leveraging existing client relationships and developing and managing referral acquisition as a prioritized process..

You can read more about how to approach it here.