When I first started, I did a body composition screening for free to get exposure. The only other program I did was at a site associated with Meals on Wheels where I did some chair exercises for the participants. The goal of that was simply to help the mainly older people with some ideas for exercises. I did that for quite a few years without any anticipation of getting clients.
Free programs are often not valued in the way you may hope. Yes, it does get you exposure but often not much comes of it. I also do NOT give any free personal training sessions to attract new clients. My main reason here is that I always do a comprehensive screening first, and I simply will not do that for free. However, I offer it as part of an initial package of 3 sessions + the screening for a package rate.