Founded on December 14, 2002, and launched 0n May 5, 2003, LinkedIn is hands-down the most popular social media site for professional networking. The website is available in 24 languages and has over 400 million registered users. LinkedIn is great for people looking to connect with people in similar industries, networking with local professionals and displaying business related information and statistics.
Efforts to combat selective exposure in social media may also cause an increase in political polarization.  A study examining Twitter activity conducted by Bail et. al paid Democrat and Republican participants to follow Twitter handles whose content was different from their political beliefs (Republicans received liberal content and Democrats received conservative content) over a six week period.  At the end of the study, both Democrat and Republican participants were found to have increased political polarization in favor of their own parties, though only Republican participants had an increase that was statistically significant. 
Flickr, pronounced “Flicker,” is an online image and video hosting platform that was created by the then Vancouver-based Ludicorp on February 10, 2004, and later acquired by Yahoo in 2005. The platform is popular with users who share and embed photographs. As of October last year, Flickr had more than 112 million users and had its footprint in more than 63 countries. An average of a million photos are shared daily on Flickr.