Quite impressive. Prediction in any form is difficult; more so when there are a million people involved.
As long as you have access to good data that is.
Even given a single sample, one can make a prediction of what the next observation will be: the same value. Once you get more samples and more knowledge about the subject, you can bring stronger statistical tools to bear to get error estimates, prediction intervals, improved models, etc.
Like I said earlier, increase in data does not always lead to improved models.
In polls like this, the more data the better as long as it is unbiased (i.e. as long as it is DATA).
-- Yogi Berra
"Who first said "It is difficult to make predictions, especially about the future (or one of its many variants)?"