Word of mouth works, but it's not enough.
If you’re currently relying on promoting your services through word of mouth, how many people do you think you’ll need to talk to every month, to grow your business to the point where you’re making your yearly target income?
Let’s calculate it together. Assuming you’re selling a high ticket program, and your target is to reach at least 50 sales. Ideally, not everyone you talk to will say yes; so let’s say you have about 30% conversion rate. You’ll need to talk to ~170 people to make 50 sales.
If you’re good at selling and you have the time, then go for it. If not, your time is best spent doing what you actually love, which is helping people.