Another reason this is dumb is that this is the kind of thing that Google doesn't much like. They don't want to index and rank content highly just for it to be mostly inaccessible.
I have no idea how much new traffic to Quora comes from organic search, but I have to imagine its not unsubstantial.
Yeah I think Blekko had a search engine monte thing where you could run a search blindly across 3 engines and see which ones were best. At least for me, no search engine came up on top.
The theory I'm working with is that its because they're all looking at the web as a series of web pages, instead of discrete objects or data.
So like a search for "2 bedroom apartment in new york with a doorman" awkwardly brings me results of web pages (that are SEO-ed to the hilt :). Instead, don't I just want a series of apartments that match my criteria?
And couldn't that data be fed from those offering this structured data in the first place such as Roomorama.com (the site I've been working on), or Airbnb or others?
Certainly content based but not QA like Answers.com. And yeah I am familiar with All Top but it's not quite the same. What I envision is a single page for each news story that is a consolidation of all of the best content on that one story.
So tweets, links to articles, photos, videos, political cartoons, wikipedia links, etc.
Personally, I think you are thinking too small. IMO there is a larger opportunity for a marketplace to buy and sell promotion for the long-tail of the web (niche content providers and small startups selling to a niche audience) across many mediums including newsletters but also company blogs, social media presences, forums, etc. Buysellads.com does it well, but I think there is room for another player who can execute in slightly different ways.
I actually have been thinking about this idea for a while and would love to chat more about it. I've been working on a travel industry startup for 2 years that has had a difficult time finding great/targeted advertising opportunities.
I have no idea how much new traffic to Quora comes from organic search, but I have to imagine its not unsubstantial.