I found today a very interesting post on Boost Your Online Presence that explains why it is important to be online. Elizabeth Mansfield is explaining the importance of Web 2.0 by numbers. You can find answers to questions like this one and more:

Do you know how many American internet users watch, create or download video?
Or who is looking at Wikepedia.com?
Are you the only person reading other people's blog or are there more?  read more »