Have you worked as (or with) free guides?

...and is it ethical? My name is Kate Bettes. I'm a travel journalist who is currently doing research into what it is actually like to work as a free tour guide working within the tips guide model. I would love to hear from anyone who is worked in this space: whether you're a current guide, ex-guide, run a free tour company, hate it, or love it. I'd like to hear your opinion in the comments below - and if you were interested in talking to me about it in more detail over a call!