Re: Paris Hilton isn't stupid.
She's a bit like GW Bush (also not nearly as stupid as he appears) in that she uses other people's perceptions of her to great effect. Lots of women take advantage of the fact that people think they're stupid. She's made a whole career out of it, and yeah, I think she's a fairly brilliant businesswoman. And she makes it look like she does absolutely nothing too.
I can't say 'no one is really that stupid', though, because many, many people really are that stupid. They just generally don't make any money at it unless they're exceptionally beautiful and have a great team of people doing everything for them, and then they don't last this long. How long ago was that sex tape? Long long ago. About three decades in celeb-years.