Question: What pornographic media and social networking site third most popular to the world's largest pornographic video sharing and viewing website registered to the Polish company, WGCZ Holding?

Context paragraphs:
YouPorn: YouPorn is a free pornographic video sharing website and one of the 100 most accessed websites in the world.  Since launching in August 2006, it grew to become the most popular pornographic website on the internet, and, in November 2007, it was reported to be the largest free pornographic website as well.  As of February 2013, it was the 83rd most popular website overall and the fifth most popular pornographic website.  In the category of pornographic websites, it was surpassed in the rankings by competitor sites xHamster, XVideos, and Pornhub, as well as the adult webcam site LiveJasmin.

Bragster: Bragster was a global social networking and video sharing website on which users dare each other to perform stunts and tasks.  The website name stems from the 'Bragging Rights' which are earned on the site.  The company is based in London, England.  The majority of the content is user generated, although some branded videos from companies such as Tango, Adidas and Wizards of the Coast have been broadcast on the site.  The site is designed to be a more niche alternative to other social networking websites.  In February 2010 Bragster was acquired by Guinness World Records.

Social media optimization: Social media optimization (SMO) is the use of a number of outlets and communities to generate publicity to increase the awareness of a product, service brand or event.  Types of social media involved include RSS feeds, social news and bookmarking sites, as well as social networking sites, such as Facebook, Twitter, video sharing websites and blogging sites.  SMO is similar to search engine optimization, in that the goal is to generate web traffic and to a site and increase awareness for a website.  In general, social media optimization refers to optimizing a website and its content to encourage more users to use and share links to the website across social media and networking sites.  SMO also refers to software tools that automate this process, or to website experts who undertake this process for clients.

XVideos: XVideos is the world's largest pornographic video sharing and viewing website.  It's registered to the Polish company, WGCZ Holding.  Alexa ranks it as the 50th most visited website in the world.

Social Networking and Psychology: Social media began in the form of generalized online communities.  These online communities formed on websites like Geocities.com in 1994, Theglobe.com in 1995, and Tripod.com in 1995.  Many of these early communities focused on social interaction by bringing people together through the use of chat rooms.  The chat rooms encouraged users to share personal information, ideas, or even personal web pages.  Later the social networking community Classmates took a different approach by simply having people link to each other by using their personal email addresses.  By the late 1990s, social networking websites began to develop more advanced features to help users find and manage friends.  These newer generation of social networking websites began to flourish with the emergence of SixDegrees. com in 1997, Makeoutclub in 2000, Hub Culture in 2002, and Friendster in 2002.  However, the first profitable mass social networking website was the South Korean service, Cyworld.  Cyworld initially launched as a blog-based website in 1999 and social networking features were added to the website in 2001.  Other social networking websites emerged like Myspace in 2002, LinkedIn in 2003, and Bebo in 2005.  In 2009, the social networking website Facebook (launched in 2004) became the largest social networking website in the world.  Active users of Facebook increased from just a million in 2004 to over 750 million by the year 2011.  Making internet-based social networking both a cultural and financial phenomenon.

Pornhub: Pornhub is a pornographic video sharing website and the largest pornography site on the Internet.  Pornhub was launched in Montreal, providing professional and amateur photography since 2007.  Pornhub also has offices and servers in San Francisco, Houston, New Orleans and London.  In March 2010, Pornhub was bought by Manwin (now known as MindGeek), which owns numerous other pornographic websites.

Fotki: Fotki is a digital photo sharing, video sharing and media social network website and web service suite; it is one of the world's largest social networking sites.  In many ways, the site appears to be similar to the majority of other popular photo sites which support a number of so-called Web 2.0 features, such as use of Ajax, tagging, RSS feeds, social bookmarking, GPS location information and Exif info display.

Hi5: hi5 is a social networking site based in San Francisco, California.  Founded in 2004, it was reported to be the 2nd largest social network after Myspace by 2007.  In 2008, comScore reported that hi5 was the third most popular social networking site in monthly unique visitors behind Facebook and MySpace.  The social networking site, if(we), formerly known as Tagged, purchased hi5 in December 2011, for an undisclosed sum and operates it today.

RedTube: RedTube is a pornographic video sharing site, which in September 2009 held an Alexa ranking within the world's top 100 sites.  By June 2010 it had fallen out of the top 100, but it made a return in mid-2012.  Its popularity has been ascribed to its non-sexual name, which is a reference to the non-pornographic video sharing website YouTube.  The website is based in Houston, Texas and has servers in San Francisco and New Orleans.

XHamster: xHamster is a pornographic media and social networking site headquartered in Limassol, Cyprus.  xHamster serves user-submitted pornographic videos, webcam models, pornographic photographs, and erotic literature, and incorporates social networking features.  xHamster was founded in 2007.  With more than 10 million members, it is the third most popular pornography website on the Internet after XVideos and Pornhub.

Supporting paragraphs: XHamster XVideos
Answer: xHamster