I give a free consultation/assessment/goal review to all potential clients who contact me for my in-home business. In the past 5 years all but one has turned into a client, and most of them have been long term.
I personally see this as a valuable piece because it allows someone to meet with you and get a sense of your training and communication style as well as you understanding their goals/health issues etc. If clients feel you are genuinely invested in them, they will become invested in you as well.
However, even if someone doesn’t immediately sign up with you after receiving a freebie, they may remember your name for the future for themselves or possibly a referral.