There are so many reasons, however this is the age of the baby boomers who are now retired and have nothing else to do, on their free time that is. I know many of us are starting on-line businesses, I myself have several websites and I am running a handful of home based buisnesses.
For a generation that had to work hard, raise a family, most of use are comfortable with computers. We can work around them and keep our minds active and also have play time. Wonderful, ways to keep your family connected with everyone living in all parts of the country, not to mention the need to stay connected for the seniors out there. Younger folks are looking and longing to hook-up, on some dating sites. I need my computer to write my books, and to get everyone I know and care about on Facebook or Myspace. Playing games on Big Fish on Yahoo.
Also, starting blogs to share and talk about issues that are important to each and everyone of us. I think of it as the age of staying connected.