Have social networks always existed?

I think that social networks have been with us since the beginning; the only difference is the name that has been given to them. Before globalization, people sent messages with letters that travelled through towns, villages, or even countries. Surely, that must have been really annoying, for it must be really stressing not to know whether your letter has arrived to the destinatary and having to wait for an unsure answer. Later, without the improvement of the electric telegraph, the telephone would not exist. Now, we can use the phone to communicate inmediately with someone and hear their voice.  The telephone entreprises take advantage to sell this service because it has been demanded by people since 1910. 


Moreover, Internet was developed in 1990, the use of Internet has increased so fast in the occidental. The majority of communications' industries - including radio, television and the newspaper - have adapted to globalization. This event also caused the appearance of new services used for work and entertainment like emails, internet's telephony, online movies, music, and videos. Also, newspapers and books are innovating with web sites, blogs and books on digital format that make it easy to read and download. 


Finally, social networks are used to communicate through messages and also, videocalls for work, studies and interpersonal relations. Nowdays, enterprises and business are taking advantage of the social networks' power to make their products or services more renovable, meaning that they are mainly using only using Internet in a strategic way.