Right, the fact it is not illegally anticompetitive per se shows that it is an answer to your original question. > Doing an anti competitive practice is legal

Right, the fact it is not illegally anticompetitive per se shows that it is an answer to your original question. > Doing an anti competitive practice is legal if you don't have a monopoly? A practice being anti-competitive (in a legal sense) depends on the act being done by a company that is a monopoly, or part of an oligopoly. For example, a company giving their product away for free is not illegal per se. Say, as part of a promotion, in order to get their product in consumer's hands instead of a competitor's product. In a healthy market, this is a valid way to do business. But, if the company that decides to give their product away for free is a monopoly, and the result of that act is squashing what little competition might exist or is entering the market, then this same act (giving the product away for free) is illegal.