As many people (and articles) have identified, online businesses are moving towards newer models to offer free stuff using advertising  and service support  to sustain.
Advertising usually means the site provides free content, and generates revenue by displaying advertisement alongside their content. The site would need to update content regularly, in order to attract returning visitors. There seems to be also a trend of user-generated content, such as video-sharing, which empowers the site visitors to contribute to the site content.
Service support usually allows users to use their product for free, charging for support when problem arises or signing support contracts with bigger companies. It is noticed that such companies have to work with lower profits, as a result more company operations are streamlined, such as reduced sales staff and marketing. Early adopters to such products also usually help shape future versions of the product.