For Celebrities Seeking Their Fortunes Working with Startup
2. If you are amazing at what you do (read: an A-Lister) then you will make far more money sticking to your day job. If you make $5 million per movie – trust me you are not guaranteed that kind of return in working with a startup. The reason I hate working on tech deals with celebs is that when things get hard (hint: startups always get hard) it is far easier for them to disappear and go make another: Movie, TV show, hit song, whatever than it is to figure out how to make the startup work.
3. You risk your personal brand for no reason. If the product you’re endorsing isn’t a home run (in a startup chances are it will be yesterday’s news faster than your sex-tape video) your personal brand will be associated with it and that could hurt your day job. Why risk it? Startups aren’t all that.
That’s Mark Suster in a very interesting/amusing post.