Years ago, publishers occasionally read—and published!—unsolicited manuscripts. Also sometimes poor immigrants became wildly successful thanks to their tireless work ethics. And America won wars! Not anymore.
The death of the slush pile means Anne Frank would never get published, these days, except that she still totally would, come on. Maybe not so much Mary Cahill or Philip Roth. But because of the internet and trial lawyers (everything can and must be blamed on the internet and trial lawyers) neither publishers nor producers accept anything that doesn't come from an agent, anymore. Oh, wait, this is also thanks to terrorism:
[Simon & Schuster] spokesman Adam Rothberg says the death of the publisher's slush pile accelerated after the terror attacks of 9/11 by fear of anthrax in the mail room.
So write a blog, instead! (Or get an agent. It is not that hard, lots of total idiots manage it.)
Anyway there is a lot of talk about how the internet is "democratizing" everything but of course every success story reported is a matter of actually having important connections (and luck). (It also helps, as always, to be independently wealthy.) Here is some really great advice from a "literary agent" and "screenwriting instructor":
...anyone can teach a three-act structure. What I want students to get in the mind set of is 'How do we write something with the purpose of monetizing it?'"
Maybe anyone can teach a three-act structure! But judging by the quality of mainstream screenwriting these days, most of which manages to be both formulaic and poorly constructed, no one actually is?