
In the beginning there was the betting market. Long before anyone worked out the basics of statistical sampling, quotas or past vote weighting, the betting markets proved remarkably accurate in predicting political outcomes.
And in recent years things have only got better. New exchanges, such as Betfair, have eliminated the bookie, and allowed customers to create their own markets. Each punter can choose to either take a bet (the normal method everyone is familiar with) or “lay” one (in effect becoming the bookie).