How do you prevent monopolies and corruption in a free market?
It isn't possible. The very idea of a "free market" is a contradiction of itself, since the bigger a company becomes, the more market share it controls, and hence the less free the market becomes for everybody else. New companies with innovative ideas cannot then penetrate the market without support from these larger organisations.
Look, a free market would result in power changing hands frequently, but that is not what the data shows. Using the internet as an example, the big tech companies like Google, Yahoo, Facebook etc, have been here from the beginning. Even when new sites emerge and suddenly become popular, most of the time they are either affiliates of the larger organisations or they are quickly bought out by these same organisations.
Free market is literally an oxymoron. It can't happen. If you don't regulate the market, then it falls under the control of the largest companies. If you do regulate the market, then it falls under the control of the government.
You sit down and say 'yes, rich, yes' and then remember that instead of saluting as you would with a 'yes, sir, yes' you instead do this:
And make the following song: