People separated in time and space, can use the Web to exchange or even develop each other's innermost thoughts, or alternatively their attitudes and desires of everyday life. It is the means of wider dissemination of personal exchange appeared in human history, far ahead of print. This platform has allowed users to interact with many more groups people scattered around the planet, what is possible within the constraints of physical contact or simply the limitations of all other existing media combined. Thus we can conclude that the emergence of the Internet brought undeniable benefits, it has become a powerful tool in the world, but like all technologies they do, it has also brought many consequences, is to make people much more comfortable, work less, and accessible to other unpleasant information, as with any development tool can also be used for malicious purposes. Internet users usually have defects, generating a large dependence of many things descuidandote personal or work. The network is easy to find good information, while another with different characteristics and unpleasant as pornography, graphic violence, terrorism, which applies particularly to children. It is also presumed to be the main source of Piracy and other evils It has produced such as spam, malware, the proliferation of viruses, phishing, etc. Many writers such as Maya Dubin offer more in-depth analysis. "I think computer viruses are human nature: the only way of life we have created so far is purely destructive." (Stephen Hawking) This was the current owner of Express Lucasian Chair of Mathematics (Lucasian Chair of Mathematics), University of Cambridge and a member of the Royal Society of London, of the Pontifical Academy of Sciences and National Academy of Sciences of the United States.
Despite this the benefits of this new technology are endless and its contribution in the field of trade can not be denied. E-commerce seeks to fulfill the needs of clients based on the benefits they seek, which means that the price depends on the enhancement of the customer, not cost, such opportunities arise when offered differ by elements of marketing other than price, which produces value-laden benefits, such as comfort produced by direct distribution through electronic software distribution. With all these new concepts are created different paths in the wide world of commerce as are the pages of classified ads. These are places where ads are inserted free on products offered, and in turn are available which offer other people, or in these places can be customers or vendors at the same time. The most common is that the product range is very wide, because in them we find free classified ads for buying and selling of mobile phones, apartments, houses, cars, computers, motorcycles, jobs, clothing, furniture, conveyances, animals, second hand , all steps from here, and the best is the interaction between the user and the system is extremely simple.