REFERRALS: 90% of my new clients come from current customers. Not only do I provide a good service that is rather hard to find but also only really applicable

REFERRALS: 90% of my new clients come from current customers. Not only do I provide a good service that is rather hard to find but also only really applicable to certain people. (It's good to know your customers), I also send out little reminders every few months that I'm open to referrals and gladly give a referral fee or a month free of my service. I find that people also refer me the first week they sign up. Which is something that is a bit of a hack. I heard this advice a couple years ago and I thought it was crazy but it totally works and is awesome. Someone finally made the decision to buy my service and it's at that point that they are most excited about it and love to refer people.