If we're going by page views then I'm sure many unsavory sites have many more. Still not mainstream - or not in the way that you think.
My point with mainstream was not views. My point with mainstream was that it will become something normal people could potentially use.
I like to think of reddit/StackExchange as the mid point between the completely disparate forums and a Facebook like interest based real-name social network.
You have a skewed perspective on Reddit. It absolutely is mainstream already, and will become more so over time.
When your website has that many uniques, and its subculture has been referenced by mainstream brands, TV shows, and continually shows up in real life (I just saw a local pizza shop that used an Advice Animal on a sandwich board outside), you are mainstream. When the President of the United States holds a Q&A session on your site, you are mainstream. When the internal drama of your website makes it onto the NYTimes and CNN, you are mainstream.
It's grown far, far beyond the internet-nerd stronghold it was a few years ago. Hell, at this point my humanities major friends are on Reddit, even if they don't comment.
Compare with Quora - which has made few inroads to any community besides "Silicon Valley Insider". The vast majority of content there is still about the tech industry and startups, and even on other topics the vast majority of commenters have tech industry/startup backgrounds. Mainstream? Really?
It may be that in the future a real-name-driven community will take the crown from Reddit as biggest community on the internet, but that's a long way from today, and I seriously doubt it will come in the form of Quora.
Shit, I just visited my Quora profile and one of the top 3 questions in my feed is "Quora Employees: Are Kah Seng Tay and Kah Keng Tay related?". This community is self-absorbed and self-referential in ways that even Reddit can't match.
What nonsavory forums have more pageviews or uniques than Reddit? And are you seriously saying that "normal people" don't use Reddit? Where is traffic coming from?
My point with mainstream was not views. My point with mainstream was that it will become something normal people could potentially use.
I like to think of reddit/StackExchange as the mid point between the completely disparate forums and a Facebook like interest based real-name social network.
They are like IRC.