Found this to be quite surprising.

In May Quora refused to tell TechCrunch how many users it has:

http://techcrunch.com/2013/05/28/quora-grows-more-than-3x-across-all-metrics-in-the-past-year/

Reading the Valleywag article you stashed, he holds no punches in comparing Quora/India with Path/China:

Finding users in emerging markets that will keep your questionable value proposition afloat is grand! Just ask Path, which proudly touted China as its second biggest user base this spring. (An inMobi survey from May found that Chinese consumers are more likely to make in-app purchases than Americans.)

Is Quora actually smart?

Clearly Quora has a quality problem—there's an entire sub-community on the site dedicated to talking about how trashy it is. It's certainly a problem the site is aware of: remaining co-founder Adam D'Angelo admitted to GigaOm that "[keeping] the noise level down is going to be focus for us." With the creation of its fantastic—and fantastically brief—weekly email digest, Quora proves that it has some gems. Maybe even enough gems to justify a business. But there's a reason you can't shout in the library—noise is everything, and Quora is rattling with crude, alienating noise. Standing between where we are now and some remote speck that resembles anything near a (rumored) half-billion valuation is a landfill's worth of junk—the academic equivalent of Tumblr's rape and anorexia problem. How will the Facebook prince clean it all out? Don't bother asking Quora.

Read more: http://valleywag.gawker.com/is-quora-actually-smart-510343042

Are there other sites like Quora?

Rob there are many Q+A sites, but Quora definitely has the minds eye of the valley. They introduced a blog product that I still don't understand. It's similar to a medium blog, but I guess quora gets all the hits/traffic, and all your thoughts/idea, for free hosting -- which I think is a raw deal.

What do you mean gets "all your thoughts and ideas"?

Sometimes a person will publish exactly the same article on both Quora blogs and Medium.

Example:

http://pandawhale.com/post/27879/the-manager-who-lost-the-north-sean-rose-quora

Neither Medium nor Quora lets you map your blog to your own website domain like WordPress and Tumblr do. Each brings you a potential audience, and those audiences overlap at least a little.

Ok, cool.  I thought it was a copyright capture and ownership of content thing.

Two things on this. Targeting India for growth is tactically smart, as its the second largest population of educated, English-speaking folks, but two, it creates an unintended consequence in that it produces a "reverse network effect," in that the site actually gets noisier and less useful as more people join and contribute.