I like this advice. It's what I began with, actually. But because the work I do is so largely trust-based, offering two 15 minute sessions once a month with followup turned out to be the way I was able to attain a steady and growing income. If I charged for those sessions, I would have so many fewer people who tell their friends about me, fewer referrals and less success all around.

I do believe my time is valuable, but I also believe expressive writing is a tool everyone should have access to. Because of this, I consider the free work I do to be service or donation. It fills my heart with joy. With that said, you are still right. There are boundaries that MUST be maintained and made clear, and if people see they can easily work with you for free, they may try to take advantage/undervalue your work.