I think this is one of those examples where nobody's rushing in because no matter how you slice it, the product is just not that useful.
I've used it a few times and because the eco system is truly about hiring dirt, dirt cheap labor you kind of get what you pay for.
Beyond that the revenue model sucks - the concept of running millions of micro-transactions and having a little piece of all the action is compelling, but again because the product use is so limited it's difficult to make signifigant revenue.
It seems like going through CrowdFlower could help a lot. Has anyone used it? I guess it worked for the author.
At my last job I was involved in a project where we were going to use CrowdFlower, but it ended up being canceled. I was always curious about how good their results are.