Porn and Prostitution

So, I was having a thought, and I want some opinions. I was just thinking about how porn is accepted in our society and perfectly legal, while prostitution is neither accepted nor legal. And I thought to myself, why is this? Aren't they basically the same thing, only one is behind a camera/computer screen? It's still exploiting people for our own personal pleasure. And in porn, it's still real people, which I think we sometimes forget. Anyways, I just wanted some feedback as to why our culture sees these two things as so different from each other. Let me know what you think. :)