I think you need to try it, or some form of social media marketing you do yourself. If not now, chances are in the future you will and may wish you had done so sooner. It reaches a whole other market and this one is going to grow- not shrink.
Make sure you keep your integrity and create a winning situation for yourself with a thoughtful offer.
We do Facebook offers the day of for a trainer not full- if they lose their time- they lose it forever. So we do a 50% off single session if they book between 11 and 2 for instance (or openings for the day) and payment is due upon booking so we know they’ll show. Trainer then gets something over hourly for their time and we may bring in someone who was thinking about it anyway.