How do you define, exploitative?
There are some well known, so-called first tier agencies, run by women, that are true pimps.
They use coercion, intimidation, threats and exploitation to have the SP remain with the agency and do the call that they have been sent to. There is no overt violence but there is manipulation.
It is not about the split of the money, it is about the coercive means used to get the lady to the call.
The average John will not know what is going on behind the scenes between the lady and the agency. On the other hand, there are some agencies that are upfront with the lady so that an informed choice can be made and the option to leave is always open with no strings attached. It is the subtle difference in the nature of the relationship, not the money, that is key.
Of course, if the agency owner is taking 60% of the money or more, then it is a strong indicia of an exploitative relationship.
It is a great reason to make prostitution completely legal in every aspect, for ladies that are independents.
Legalizing prostitution through agencies is a whole other kettle of fish. For example this weeks police raid at Club De Lotto and the charges of human trafficking make it clear that legalizing prostitution as an industry, distinct from that of independents, is something that society does not need.