The advent of the Web 2.0 and the explosion of social networks, due to widespread use, especially young people, are changing the way companies compete. The information and communication technologies have led to sources of opportunity for the business sector, the interactivity that can be achieved on the website of the company, improves the level of identification itself, the relationship with customers and knowledge of the opinions on satisfaction of products and/or services received, causing more responsive to the expectations of the customers/users with improvements or innovations in products/services.On the other hand, viral marketing is a result of the dissemination of comments and opinions made by actual or potential users about something specific such as a product or service within the field of online social networks, the active participation of the companies on the web can avoid or reduce negative trends. Thus, the explosive growth of online social networks like Facebook, Twitter, Flickr, MySpace, LinkedIn and almost constant connectivity through mobile devices can be an opportunity or threat to any company or institution.