no doubt that fame is fetching a lot of people millions of dollars by building brand, and its somehow becoming a normal way of life in the society today. well fame has its advantage and also the disadvantages. and i guest this part you have mentioned is one of the advantages. i can see how celebrity nowadays promote their brand and become more wealthy. how this is done is that most of them build company secretly and run promotion or ads for it without people noticing that its theirs. while some sign an endorsement deal with a particular company for their image to be used for promotion and they get paid. but the sad story is that when celebrity career has been ruined by their mistakes, they cant be signed for any endorsement deal. or they cant even run their own promotion, because your business succeeds as a result of followers and fans. when your followers get dissatisfied by your services. because that will surely be the end of the whole story.

the truth of the matter is that not everyone can succeed by building brand and succeed from it. this is strictly for celebrity.