Royalties and Residuals
In low or under funded production salaries are sometimes paid at the back end of the productions in salary as well as royalties from ticket sales and DVD releasing.
Although in smaller productions, actors will usually get less salary in lieu of a larger share of royalties. If the film is unsuccessful the producer does not have to pay a salary and does not lose as much money. If the film is a success, the actors receive good royalties and getting paid "residuals" over a longer period of time.
Royalties may be negotiated not only for actor/crew salaries/fees, but also with other service providers, e.g. distributors, post-production houses, and so on.