There are as many benefits as problems of being a celebrity, like a film star or sports personality. As a benefit, they can get advertising contracts to earn more money but also they can get a lot of enemies because of what they represent. In my opinion, it is has more benefits than problems.
Companies, which are trying to get recognition from people, look for an influential effect. Being a celebrity means they influence people, therefore this will attract companies that want you to present their products. Depending on how many people they reach they get more money from your contribution to the business.
However, as a celebrity, as a person who is always on stage, they will always get evaluated. Which means, every act will be in front of the eyes of people. This will bring some dislikes in addition. Getting peoples dislike creates arguments, arguments create fanatics, fanatics turn into enemies. Although, there is nothing as a bad advertisement, and you can turn this situations into job opportunities as well.
In conclusion, benefits are always more. Celebrities should always focus on taking advantage of all kind of situations to get all the benefit possible. Problems are only problems if you think they are problems.