How Augur Works [video]
augur.net
augur.net
Here are two of their main threats:
(1) Fraud. This may have taken down intrade.com and took down the Bitcoin exchange Mt. Gox. One start-up that successfully avoided this problem is PayPal.
(2) Being shut down by the government as an illegal gambling site. They need to secure a no-action letter from the Commodity Futures Trading Commission. (See the Wikipedia article on PredictIt.)
I plan to follow Augur with interest and wish them every success.
Prediction markets are a well-defined interaction between people. Blockchain technology lets us build anything in that category with near-zero transaction costs and huge censorship resilience.