Again from Yes! 50 Scientifically Proven Ways to Be Persuasive: Don’t give away anything for "free" because the "the value of an item declines when it is offered as a gift."
So, instead of offering in your Yellow Pages ad (you’re still doing those?) a "Free Consultation," try offering a "$250.00 case analysis at no cost to you." Your clients will value your continuing services more highly, and they’ll feel like they’ve already gotten something of value from you to begin with — making them more likely to reciprocate and hire you to take their case.