I've thought about this with the stock market and predicting that it would go up or down. After enough predictions, one would have an email list of people that saw one accurately predict the stock market after n times. This could then be used to request payment for future predictions.
While I can't state that this breaks any laws, it is possible it might somehow. However, even if it doesn't, it's a really fucked up thing to do because it's conning people out of money using a scam. I highly recommend against it and responding to emails of people predicting future outcomes of events that vary wildly with any certainty.