[thaumasiotes]

Well, assuming a standard wisdom-of-the-crowds problem like "how much does that cow weigh?", the answer is drawn from a continuous interval and the probability of choosing the right answer is necessarily zero. Yet, the fact that that's a standard example of a wisdom-of-the-crowds problem suggests that the zero probability of being correct isn't really a big issue.

For a slightly different example like "how many jellybeans are there in this jar?", the answer is drawn from a discretized interval, but I feel pretty safe in assuming that the odds of any one crowd member getting it right are well below 50%.