I've run a movie website for the last seven years, and my first advice is: Do it for fun.
I know people who were racking up 750,000 pageviews a month and not making a dime... basically all their money went to their hosting plan. They were cranking out all kinds of pieces on any subject, large or small, to increase pageviews, and working around the clock, going to film festivals out of pocket, etc. and basically went broke doing it and had not much of a backup plan, so they're all scraping by on other jobs now.
So, number one: Don't quit your day job.
There are easier ways to make money, but if what you primarily want to do is write for the sake of writing, then keep focusing on content that interests you and find genuine ways to make it interesting for your readers. 90% of every site's traffic is the index page. Even large traffic sites don't generate much return readership and it's disappointing.
What you want to do is commit to a set of ideals that represent why you're doing it. For me it was that I wanted to be a better writer, and a better movie critic. All else was secondary to my mission. That's how I developed a reputation among the readers I do have, and among the film criticism community.
I may not make a dime and I may not be famous, but my respect for proper journalism got two other professional film critics to write for me and now we represent significant voting power in the awards season. For a site that is small fries we have a lot of clout... and that its perks....
Not every site that the editors/writers are passionate about takes off... Sometimes it's the luck of the draw, unless you have millions of dollars to throw at the public, because the internet is much more crowded now than it was if you had started ten years ago. But if you don't have a passion for what you're doing, and you don't take it seriously in your writing and develop your own "voice" that sets you apart from the umpteen zillion other sites that write about the exact same things you do, then building a following will be very difficult.