The following is taken from David’s interview with Rachel Pryor in 10 Super Coaches.
Do you recommend offering free coaching?
I offered free coaching to my first 3 clients, for 3 months, and they helped me to identify the documentation I needed for my practice. After 3 months, I found I began to resent giving away for free, so I stopped. I also occasionally offer free coaching in return for some service, however this is not very effective for me.
Never get into a situation when you have offered free coaching without a limit on the timescale.