They remain open because of an investment support from Sequoia Capital. They also said that it was founded by early commerce pioneers of PayPal.\n\nI too am surprised that there aren't any ads, yet.\n\n"Founded in February 2005, YouTube is a consumer media company for people to watch and share original videos worldwide through a Web experience. Founded by early commerce pioneers of PayPal, YouTube allows people to easily upload, tag, and share personal video clips through www.YouTube.com and across the Internet on other sites, blogs and through e-mail, as well as to create their own personal video network. With investment support from Sequoia Capital, YouTube is set to become the Internet's premier video service."
How does website like YouTube make money or at least maintain itself financially?