4.2 VERTICAL SOCIAL NETWORKS
The users of vertical networks form communities who have similar reasons for using the application.These reasons,witch can be personal or professional,may incluide:

1. SHARING PROFESSIONAL INFORMATION:  Linkedln is the most popular network for all kinds of professionals.
2. SHARING GENERAL INFORMATION:  With FriendFeed,people can create private groups to share information abaut projects,organise events and exchange photos or experiences with their friends.
3. SHARING PHOTOS:  Instagram,Flickr,Pinterest and Picassa are popular.
4. SHARING VIDEOS:  Youtube,Dailymotion and Vimeo are common examples.
5. LIVE STREAMING:  Skype,Twith,Livestream and Upstream are often used.
6.  there are many other services related to sports,cinema,books and other topics.