Regular client discount buy 5 get 6th free...

[bettercallsaul]

Or
after first five visits get 5 % Discount, prefered client rate;
After 10 visits get you get the 10% Dicount, gold client rate;

Any other suggestions welcome

I like the idea,when you consider the lady gets regular income from a guy she already knows,it could have some merit.When you consider she has to yet again have sex and pretend she likes the same old sweaty pervert as the last 10 times she may want to charge more