Why don't you charge some % from every completed tour but ask for an annual fixed fee instead?

We created our service based not on a traditional commission basis because any commission will be much more than a fixed annual charge. Try to calculate by yourself! If a standard full-day tour costs 200-300€ and we charge 20% commission it will be 40-60€. And this is commission only for 1 tour!

At the same time, our annual membership cost 30-70€ per year depending on the country. But how many tours can a guide make in 1 year? 10? 20? 50?
Our registered tour guides make a minimum of 10 tours per year and pay us a 40-60€ annual fee instead of 400-600€ for 10 tours commission! Big difference, right?

Our idea was not to interfere in any negotiations between tour guides and tourists! Of course, it brings more responsibility to a tour guide but this is his/her professional activity and they know what they do!