As of February 2010, there are approximately 545 online poker websites. Within the 545 active sites, about two dozen are stand-alone sites (down from 40 in March 2008), while the remaining sites are called “skins” and operate on 21 different shared networks, the largest network being iPoker which has dozens of skins operating on its network. Of all the online poker rooms PokerStars.com is deemed the world's largest poker site by number of players on site at any one time. By May 2012 PokerStars.com had increased their market share to more than 56%.