Using Referral Sites to Grow Your Counseling Practice

Due to my niche practice, I've never had to use online referral sites such as Psychology Today.  My practice works directly with probation and parole departments for referrals, so I've never had to try other referral resources.  

For a short time, I worked in a general private practice with other counselors, accepting insurance and seeing people on a referral basis, but the referrals came into the practice and were dispersed to us based on availability and specialty.  Again, never had to do any referral development on my own.

I'm curious if anyone is willing to share some real numbers of the amount of referrals they receive each month through referral sites?  Is it worth the money?  I'm hoping we can create some honest dialogue about the best ways to develop referrals.