The Point Of No Return (Financially)?

At what stage do you foresee you stopping working in the online adult industry because of hitting the point of no notable financial return for the time and/or money invested in the industry?

For example, im pretty sure that once revenues drop below 25% profit on investment that we'll be migrating further and further in to the mainstream world, at the moment, that point is a long way off but, getting closer day by day.

At what point do you think you are going to call it quits in the adult industry and do you think that point will be drawn financially, motivationally or because of saturation of the industry?

Regards,

Lee