This interactive Web page from the Boston Consulting Group characterizes the Internet economy and its impact on commerce and small-medium enterprises and benefits to consumers in the G-20 nations. (The site is free to use, but registration is required).
For example, here is the Internet Economy display for the US (click to zoom):
It turns out that many people would rather do without satellite navigation, fast food, chocolate, alcohol and coffee than skip the Internet for a year, but they generally prefer sex, their cars and showering to the Internet. Exercise falls in the middle -- about half of us would rather give it up than the Internet, as you see here.