Genius is in the same boat. A decade old, failed premise (turns out people don't actually want to annotate everything), failed expansion plans (so... back to lyrics then), no business model. At the mercy of the VCs, they'll eventually be passed around for $10m or $20m like MySpace or Tumblr.
These companies are this start-up generation's About.com (or the latest eHow).
Simple rule for anyone doing a knowledge service: if you put the profit motive over the knowledge motive (which is the only choice if you take a lot of VC), your service will end up in the dustbin of history, no exceptions.
It could disappear tomorrow and leave barely a memory.
Worse yet, the site is full of dumb answers as well.
The problem IMO is the scale of the opportunity relative to how much money is consumed.
There are great businesses at every increment of enterprise value from $5 million up to $5 billion. We just need to realize this, and stop judging greatness by the pure size of the exit.
I think Silicon Valley could learn a lot from Hollywood in so many ways. One is how we think about "greatness". Is there the equivalent of a "great indie flick" for software companies? Or will we continue to use "exit value" as the only yardstick?
[1]: "especially Teams, where we are starting to close many huge deals and becoming a hyper-growth enterprise software company very quickly" "And we want to make it possible for knowledge workers everywhere to use Stack Overflow to get answers to the proprietary questions that are specific to their organizations and teams."
SO, like Trello, took a long time to find a business model (honestly Trello never really did); it seems clear that SO Jobs didn't work, but enterprise sales is the key, just based on what they emphasized in the announcement. Using the SaaS website as a loss leader advertisement for the shrinkwrap software is an interesting model: I see it as somewhat similar to the old 'give away Unix and C free to universities, sell System V to the companies those students work at' model, modernized for the internet age.