Mega-Sites on top of SERPs...Does More Content Mean more success???

[bobo.cx]

I've noticed that many websites that rank high with one or two keywords have hundreds - perhaps thousands of pages. They have a lot of content per page.
Just wondering if someone has a website that is well optimized, relevant backlinks and has at least a few thousand pages that have basically a thousand words per page (and pages are added every day) - will this website eventually become an authoritative site and possibly have the chance to rank in the top three of a two KW (popular) niche?

Please answer only if you have a website of this calliber or experience in building mega-sites. I'm not interested in people who "think" it should be this way or not - I'm not trying to be a jerk - just like to know what your EXPERIENCE of this is. Thank you.