The idea is as simple and useful: each new user becomes a sales officer of the company, because the message spreads so epidemic and contagious. The essential elements of viral marketing are:
• low external contacts;
• high interaction with the ability to enter the registration form, numbers recall automatically jump link to access the web site;
• high customization of the content of the offer;
• strong predisposition purchase by users who have specifically requested to receive offers purely commercial for certain products / services.