Metaculus is a website where users estimate the probability of a future event occurring with in a certain time frame. The site behaves a bit like a prediction market but allows users to assign probabilities between 1% and 99% with greater payouts or greater losses associated with more certainty either for or against the proposition.
For example I could pose the claim: Everything2.com's write up generation will be greater in 2018 than it was in 2017. From there, people could assign the probability they think best represents the claim. Alice looks at the phenomenal out put in November 2017 and the general trend from the last couple of years and concludes that it will be greater with 75% certainty. Bob looks at the site trajectory overall and concludes that on a given year the number of published write-ups will go down and assigns it 25% certainty. Charlie has no idea and just assigns it 50%. If the claim resolves as true then Alice will get a couple dozen points, Charlie will get around five just for participating, and Bob will lose several dozen points. Bob's losses are somewhat greater than Alice's winnings. This trend of losses being greater than winnings becomes more and more pronounced at the ends of the scale decreasing the temptation for users to try and maximize gains on anything less than a truly sure bet. Users' scores allow them to gain new levels with new powers not unlike another site and users can make their estimates public at the time they make them or keep them secret.
The median and mean values of users' predictions are visible to everybody but the "metaculus" score which takes users' ranking into account only is visible after the closeout date or to users who are level five and higher and who are willing to spend a significant number of Tachyons, the sites currency. Metaculus has also introduced non-binary choices where a range of possible numeric answers are provided with success being defined by having the actual number show up in your range. Ranges can be narrowed or widened with corresponding increases and decreases in pay out.
While it's too early to really say Metaculus is poised to become a major force in information aggregation if it gets enough users. The site, at present, has a strong bent towards STEM but it's touched on politics and finance and it has no rules on what can be posed as a question apart from it being about the future and having a unambiguous true/false answer. If you want to get involved the site can be found here, some good tutorials here, and the score board is here. If you think you have any deep insights into how the world works this is a great site to test them and I'd encourage everybody to give it a look.