The answer to How many users does Quora have? is buried in their fundraising announcement:

According to AppData, 20K daily active users and 180K monthly active users log into Quora through Facebook Connect — Bear in mind that this is a small fraction of its total number of users, which Cheever and D’Angelo famously never reveal. “[The site] grows every week,” D’Angelo said, “I don’t really think of mainstream as a binary thing. I think that as it grows bigger, more and more people will use it to tell their stories.”

20k daily actives, 180k monthly actives.

At a $450 million post-money valuation...

Quora is being valued at over $2000 per monthly active user.

Mother of God.

See also: What's a Facebook user worth?

Compare to Quora's answer to the question: [from Quora's community...]

I love this sentence from Adam D'Angelo:

"We've built an incredibly strong team so far but there is only so much we can do with 30 people, and the task we are faced with is different with each new order of magnitude of usage we get to."

Source: http://www.quora.com/Quora-company/What-will-Quora-do-with-the-50-million-in-funding-it-just-received/answer/Adam-DAngelo

P.S. -- The Quora deal was done in days, not weeks. http://www.businessinsider.com/quora-josh-hannah-matrix-partners-2012-5

What is Quora going to spend the money on? AWS. http://www.businessinsider.com/quora-50-million-round-amazon-aws-ec2-2012-5

Also, Quora was on the market for a while, so maybe this deal was done quickly, but overall, not so.

I wonder how little Quora pays its employees -- if it only spent $7 million over 3 years then after you subtract the cost of AWS and infrastructure, the answer is, not much.

Especially since they indicated that most of the new money was going to be spent on AWS.

Om Malik is not impressed:

http://gigaom.com/2012/05/14/quora-gets-50-million-q-why-a-because-it-can

From the article:

The question here is why does this service merit such a high valuation. I mean its traffic at best can be described as middling. lot more fly-by traffic from search engines, but is that enough to justify their valuation. Its mobile applications is meh and more of an afterthought. The design of the service is forgettable. Some members of the team have left to work for other companies such as Pinterest and Facebook. The only thing that is actually good about the service is some of the content contributions and the discovery of content.

Here's why Matrix invested: http://www.forbes.com/sites/quora/2012/05/14/why-did-josh-hannah-invest-in-quora/

"There remains a enormous pile of information tied up in people’s heads, and a Google search fails to unlock it.  Quora is attacking that pile.  A lot of that information is stuff with multiple points of view — the wiki model, for all its strength, sucks for topics where people disagree.  The articles twist themselves in knots trying to balance everything.  Quora can handle that type of issue much more elegantly, because it is inherently built for that kind of content.  And it turns out, a huge portion of what you want to know and search for is that kind of content."

won't you say that word-for-word this is true for Surfmark as well :)

Actually, Vivek, yes. Maybe Josh Hannah would be interested in Surfmark too?

A few comments. Valuing based on $/MAU isn't the right metric to focus on. It only takes two interested investors to tango for a chance at an outsized return. Second, the current meme is to engineer hyper-growth and then browbeat momentum investors into paying up. Because these folks don't have to do that, they can focus on doing what FB and Twitter did, which is to grow much slower and focus on engagement/retention, or stickiness. Now, they never have to raise money again. Either it will work, or it won't. Finally, another way to think about the valuation -- for $7m, 30 people built what is today Quora. Imagine what more money, resources, and time could build?

One of the Valley’s favorite parlor games over the last year has been to debate what the future holds for Quora, and specifically, to speculate who will invest in the company moving forward. All rumors aside, and acknowledging my strong bias in favor of the product and company, I firmly believe that Quora is one of the most important, impressive, and disruptive social software companies that exists in the market and, therefore, presents a rare opportunity for venture capital and a potentially outsized return.

Before I lay out my arguments as to why I’m so bullish, I have to note and address the most common refrains lodged against the company and my responses. “They have no revenue!” That doesn’t matter yet. “I don’t use it anymore.” Try not to extrapolate from your own behavior. “I don’t like the boards.” The boards are just a tacti to refer traffic, and the only issue is that board-activity ends up in your newsfeed. I agree Quora should fix that, but it’s a small problem. “The newsfeed is noisy.” Well, stop following one thousand people or topics, or just search on the site. “It’s not growing.” Quora isn’t totally focused on growth yet, but they are laying the foundation for it, especially with one specific hire. They are just finishing their product. It was a long beta. “They haven’t nailed the social aspect.” I’d say this is actually a valid criticism — more on this below.

People know I’m bullish on this company, so I’ll share how I articulate my rationale when I speak with others: The market for search, if graphed against the size of a keyword search, roughly follows a power law distribution. Some refer to the shape under the curve as a “dragon,” with a head+body and a tail. In the “head+body” of the dragon, you have traditional search — the short keyword strings we enter into Google, Bing, Yahoo, and other major engines that have provided these companies with business models that exert incredible leverage. There is a big area under the curve for the head+body, and there’s stiff competition among those larger companies to manage fixed costs and maintain market share.

Now, when we move our attention over to the tail of the dragon — what people refer to as the “long tail” — we see it what on the surface appears to be a very thin line and small area under the curve. However, in power law distributions, the area under the curve in the tail is actually equivalent to the area in the head+body, which means the size of the market is theoretically similar, though there’s a reason Google hasn’t gone after long tail search and why Facebook hasn’t gone after questions.

The long tail is a hard nut to crack because (1) it’s hard to police and (2) it’s hard to build a business model around. Yet, we must remember that every question pumped into Quora is, in fact, a long tail search. By encouraging users to write out grammatically-correct questions, Quora has trained its users to revert back to searching by asking questions (as humans do in real life) rather than crude keyword arrangements.

The people that contribute to and/or follow a Quora thread make up the market for that long-tail search query. And, in order to address the root problems in long-tail search (policing and revenue), Quora has deeply integrated two features in response: PeopleRank and Credits. PeopleRank is a generic term to capture all the algorithms and administrative controls that provide a policing mechanism for the site. People monitor the site, organize topics, watch for bad actors, and surface the best or most relevant content. Quora’s credit systems creates an economy for all actions taken within the site to reward specific behaviors; eventually, one can picture the credits coming together to help monetize some of the long-tail searches that occur within the site.

Details aside, Quora also fits into a larger, evolving trend. The world is moving away from centralized systems and embracing the crowd. Whether or not you believe the crowd is wise, or rather if you feel that the masses are asses, there’s no denying this shift in many area. Look no further than crowdfunding, for instance, a phenomena encapsulated by the rise of Kickstarter and the recent JOBS Act legislation. At its core, Quora is a crowd-sourced platform, and if they’re able to enforce their policing structure and build a real business model around credits and other features, they have a chance to generate, distribute, and deliver excellent long-tail content to other places such as media brands, educational institutions, and any other entity that’s willing to pay for specific content.

I will admit, despite my overall bullishness, that Quora has made mistakes. Every startup does. Even though I use the boards, they were poorly introduced, managed, and designed. Credits are smart, but they weren’t explained well to users. Many new users who come to the site aren’t welcomed overall, nor do they know what to do. There are some legitimate concerns that the site won’t be as “social” experience as others. They haven’t built an API yet. They haven’t tested lightweight text ads against certain threads yet, though one could make the case it’s too early to try. They haven’t seeded content by going after key knowledge communities in other verticals, though they have seen nice organic growth of content in the major content areas of politics, finance/economics, sports, and entertainment (including movies).

It is easy to list out these missteps partly because there are such expectations attached to this particular site and service. While it’s important to note these missteps, they are — to me — trivial when considering the overall picture of what this company has already achieved. The site and its contents emit a feeling of authority and fidelity. It has a “permanence” about it. When I go to the site, I have the sense that the content on the site will be there, forever — some of it will evolve when the crowd feels compelled to update it, and some of it will just live in on for others to benefit from. It is a site that doesn’t look like any of the others out there — it is an outlier, what on the surface looks like a Q&A site but is much more, a slick engine driving a complex economy of information. In terms of investment, my belief is that Quora stretched their Series A investment to the limit and accomplished a tremendous feat. Whatever the market will bear for their Series B will have been hard-earned, and in my opinion, worth every penny for the outside shot at owning a piece of what could be one of the most dynamic human knowledge systems in the world.

P.S. One morsel to chew on: Check out this pie chart of the top 10,000 “Wikipedians” broken down by the amount of “work” they do. Some of these people do an incredible amount of work, entirely free and anonymous. This presents two insights: (1) Quora has built a judgement layer on top of facts (Wikipedia) where contributors may actually be known and earn reputation; and (2) a very small group of people working in concert together can potentially create massive economic value — Wikipedia is a Top 10 site.

I wouldn't have believed you until I started to see the numbers from Bing and Google and Facebook and Twitter and Pinterest referrals to PandaWhale pages. PandaWhale content has only existed for less than two months. Quora has the benefit of years of content.

Quora and Wikipedia are seeking to be THE BEST source of content. PandaWhale is not The best sources -- we just like to be a place where users can save anything socially and on the public web where blogs, Wikipedia, and Quora live too.

Given the amount of traffic we see from just a handful of people posting on PandaWhale, I can see the argument that says Quora has amassed a great nucleus of content creators.

But Quora has a downside to it: I've seen them make some community members feel undervalued -- or unvalued! -- and those people associate bad feelings with the Quora brand. I sincerely doubt they can repair that.

Wikipedia has fewer than 100K 'active' editors per month... and if Wikipedia was raising as a private entity, it'd be easy to make the case its valuation should be way over $450MM.

My guess would also be that that fewer than 180K 'active' users log-in to Demand Media sites per month... but that doesn't prevent them from having a public-market cap of ~$700MM. The revenue from non-logged-in readers is more important than 'active' logins.

Quora's valuation is impressive by many measures... but I don't think 'monthly logins via Facebook Connect' is a relevant denominator. Logins via all sources would be better, total regular (non-logged-in) readers even more revealing.

Gordon, that's an excellent point. 1-9-90 rule strikes again.

Do you have links for the Wikipedia and Demand Media numbers?

Sure!

Active registered Wikimedia editors with >=5 edits, March 2012: 85.09K (+0.2% compared with February / -4.5% compared with the previous year)

via https://blog.wikimedia.org/2012/05/08/wikimedia-highlights-april-2012/

(Notably, this is inflated by 'all Wikimedia projects' and also by some role/bot/sockpuppet accounts, but shrunk significantly by the 5-edits-or-more filter and leaving out anonymous edits.)

Demand Media market cap: http://www.google.com/finance?q=dmd

I don't know how many registered active users Demand Media and its affiliates/customers have -- when totalled up for every commenter on every property it may be a lot. But as their content seems to come from paid freelancers more than community volunteers, my suspicion is that their own comparable 'organic' registered userbase of contributors is smaller than either Wikipedia or Quora. And yet their traffic justifies a bigger public-market capitalization than Quora's raise. (I know I'd rather own stock in Quora at its post-money than Demand Media at its public market cap.)

Thanks Gordon.

Interestingly, Wikipedia and Demand Media and Quora are worth a lot less than, say, Twitter.

Does that mean more participants are worth more, even if there's higher variance in the quality of the participation?

In the alternate-universe where Wikipedia pursues revenue and has a market-cap, its market-cap might be higher than Twitter's at current traffic levels.

Editors vs. tweeters, reference vs. communication are suitably different that I doubt the 'participant count' of each is useful for comparing their values.

Views, activity, intent, engagement are all confounding factors.

Though, if you could only see a person's Wikipedia lookups, or who they follow on Twitter, which (for curiousity or economic value) would you prefer?

I'd prefer who they follow on Twitter.

Wikia is the Wikipedia that pursues revenue. I'm not sure what its market cap is.