Ask HN: What inherent traffic drivers exist for reddit-clones?

So, Ms. Foo can blog her heart out about her favorite hobby without telling a soul or attaining any links, yet she will still be found (to some degree) via search engines due to the inherent SEO of her blog title, pages of content, etc. (all blog-SEO specifics aside for the sake of simplicity).

If Mr. Bar launches a reddit-clone for his favorite topic, tells a few like-minded friends about it and fills it with some initial links and intelligent discourse, I suspect that there won't be as much inherent search traffic. The front page contains links and would always be changing, and comment pages might be too narrowly focused. There doesn't seem to be an obvious opportunity to say "hey -- here is our site topic, and here are some naturally-used keywords to back it up."

I first discovered reddit a few years ago because a fellow developer I respected said "yeah, I found that on reddit." I discovered HN recently because same developer said "hey, much better focus and discourse on HN." I'm not sure how I would have discovered HN, for example, without word-of-mouth of some kind (in person or online).

Am I missing something? Should Mr. Bar have a static, expository front page or something?

(Yes, I am thinking of becoming Mr. Bar for one of my favorite topics: modern music production. Currently if I hear a new radio hit and want to quickly google it to see what others think of the production values, I am bombarded with lyrics, ringtone, and mp3-downloady results. That's getting into a whole other discussion though.)