Introduction:
Companies after ever increasing the speed of using of internet and Social Networks by individuals decided to use Social Networks to become more and more popular in terms of their banding strategies, positioning, marketing activities, customers services and feedbacks, setup connect with people of e-CRM and alike. People use Social Networks in order to communicate, share their ideas, and use the flow of information and other means of publishing information about themselves.

Although since 1990s, using of internet, many Social Networks and internet tools had emerged, it was not popular. Recently, through the development of social network in friendly atmosphere and with less difficulty in terms of functioning if you are, this service (social network service) has become part of people's lives.

In terms of clarification of analysis on customer satisfaction, customer retention, and customer relationship management and customer feedbacks, Social Networks play a pivotal role. As a result companies have tried to utilize Social network services in order to better serve customers and get other various objectives. Most companies recognized that online networks (SNSs) like Napster, Facebook, and Twitter and so on are the best places to them in order to highlight their brand image whereby they can increase their market share, and sustainability.

What is a Social network?
It is considered as a platform whereby social associations will be built among people and information sharing will be facilitated. Through Social Networks sites information that is personal and relationships can be shared and users can stay in touch.

Most of SNSs provide a personal page for posting, ability to look for friends and other issues like updating profile and personal data and have the ability to restrict and/or disguise the mentioned information by page owner from the eyes of public or specific people.

These Online facilities (SNSs) have improved the movements of individuals on online tasks, especially in the mentioned Social Networks for the purpose of maintaining friendships regardless of distance (geographical limitation). Not only that but also it enables visitors to find better jobs and partners.

About the acceptance of these sites by people, companies have become interested to try this process whereby they can sell their products and better serve customer 's needs and wants and through analysis of consumer buying patterns and their feedbacks they can fine tune their decision making process as well as their strategies.

Below information reveals the fact that how rapidly number of Social Networks increase since 1997.