The evolution of the Internet has allowed the creation of new communication and working tools for businesses as well as for individuals. This paper will focus on a specific category of these tools: social networks. It is necessary to distinguish between non-virtual social networks, which have existed for centuries (membership in a political party, a Sports club, a fraternity, a religion, a bridge club, etc.), and online social networks, which are exclusively based on the use of the Internet.

Web 2.0 has brought about the evolution of social networks. They are increasingly used by internet users and reach a vast audience. Students and teenagers were the first users of these sites, making them the precursors of current social networks. It is also essential to know that currently, for many internet users, using these sites is considered a social activity in its own right. Today, there are no less than 1.43 billion users of social networks worldwide in 2012 (19% more than in 2011), and growth of up to 1.85 billion users active at least once a month in 2014 is expected. This amplification makes social networks a leading market, which can no longer be ignored by companies.

The corporate world soon understood the value of using social networks, for financial purposes and promoting the management of their e-reputation. Some companies have decided to use them for business purposes, to involve their employees and sometimes their customers in the life of the company. Today, all companies are dealing with social networks, which allow them to manage their image, to grow financially and to enrich their experience in the web market that offers all new opportunities, previously non-existent. Creative employees are thrilled, and we can see that new professions have emerged with the advent of web 2.0: social media manager, community manager, social media application manager, web content manager or search engine marketing specialist.

In addition to their role in computer science, social networks have a sociological dimension. Even before social networking on the Internet, the concept of networking had been a growing success in the Social sciences for several decades. In his book ” The Sociology of social networks “, Pierre Merckl√© explains that “the pioneering work of Jacob Moreno, Stanley Milgram, the anthropologists of the Manchester School (John Barnes, Elizabeth Bott…) or the sociologists of the Harvard group (Harrison White, Mark Granovetter…) have brought out a whole set of concepts, models and empirical research, constituting this” sociology of social networks ” : this means taking as objects of study not the specific characteristics of individuals (their age, their gender, their profession, etc.).), but the relations between individuals and the regularities they present, to describe them, to account for their formation, their transformations, and to analyze their effects on behaviors”. However, this paper will not focus on the sociology of online social networks but will focus exclusively on their concrete uses and the consequences of their use in the context of web 2.0.

This document will attempt to answer the following question: “Does the impact of social networks on companies have a key role in their image?”. To do this, we will explain in a first part the role of online social networks and tell where they come from. In the second part, we will study the consequences of social networks on companies, the obligation of a necessary adaptation that will offer them new opportunities but also potential risks. Finally, in a third part, we will respond directly to the problem by analyzing the direct consequences on businesses and consumers, and then we will end up asking ourselves whether or not social networks are essential to the growth and sustainability of the businesses that use them.