For these days, the situation on items relating to the Free Competition has had two interesting examples, in different sides of the world. Here in the United States the controversial takeover offer by 44 billion dollars that Microsoft has done by Yahoo.com has shaken the market today and is the subject of analysis among antitrust experts and financial specialists, as the operation will be analyzed in detail by American regulators. Across the world, in Chile, the Chilean Antitrust Court ruled finally on the merger of two major retail companies as DS and Falabella, rejecting the operation. In its foundations of the decision, the Court says that “the adoption of the operation consulted, would produce a substantial and lasting decline in the conditions of competition in a market that involves very important part of the decisions of consumption of all Chileans …. harmful expected - in terms of welfare - the prices, quality and quantity of products”. It says that of Microsoft offer by Yahoo.com - with all businesses involved - is the reaction of the giant of Windows fronting the relevant undisputed position that Google now occupies in the advertising and search contents on the Internet. In both cases, these are operations called M & A (Mergers and Acquisitions) that generate concentrations of market participation and certainly in the size and influence of companies. The major index of M & A in a market means, in general, adjustments to the size of them and greater influence of the dominant players, which should aim to benefit the consumer, so that the efficiency and dynamism own market, it also added the consumer welfare, as fundamentals of a serious analysis of each operation. The work of the regulators should be technical and accurate, but that its decisions involving a disincentive to free market development. Also, the huge Internet market is very shaken by the new antitrust case will affect Microsoft and which may affect the relevance of the company that holds Windows; then, a good number of factors relating to the practice and actual functioning of this important segment could de studied. Now the American “trustbusters” will give their opinion on what may be one of the most important operations for the year in the Internet market. Both cases, one Chilean and one American, are great opportunities for the analysis of Free Competition and regulation, without a doubt, an incentive for joint study, not only for economists and lawyers, but for a general public, which increasingly demand more information, but it also has the duty to reach out to the new realities that the dynamic market structures pose for their own benefit.