Or, they make at least 1K per night dancing.
Anyway, this is a pointless line of argument. We cannot establish the causality of Jessica Simpson's success through appearances, or by conjectures about probability of success given various initial conditions.
Certainly, this is a multifaceted issue; at least the points of managerial control (how much has her father influenced her career, for example), luck, and other environmental factors are equally open for investigation when trying to discern the origin of her success. Regardless, this is a historical problem, and not a scientific one.
Attempting to inductively argue about success from isolated cases is not only naive, it's strictly irrelevant to the truth of this particular case. If anyone wants to take the issue up seriously, I suggest perusing all the biographical materials available on Jessica Simpson, as well as all primary and secondary evidence available... of which there is much.