Money. Spent by American Dream Safari, but also by any true Anthrotraveler, in order to facilitate the clients' experience. Often items on the itinerary need to be arranged. A seat at a table in a joint that doesn't take reservations. A spontaneous, but perhaps pre-arranged, encounter with a legend who's time is precious but is willing to visit with us wayfaring strangers. Comfort in knowing that it's alright to take photographs.
Cash can be a messy thing, exchanging it can be awkward. A key element of Anthrotourism is making a positive economic impact where it is rightly appreciated. Honoraria is a first class way of showing just how much the experience means.