It is very easy to communicate with others if they have internet access. Most young people who have internet access would have signed up with myspace, friendsters and would know how to chat online. It is convenient to share information and updates of oneself. I myself have not only one but a few blogs, each for different purposes.
I know my brother has a blog but then he still has yet to post his newborn daughter's photos on his blog. Having a blog does not necessarily mean that you have the time to update it regularly. People can use blog even for business purposes. It is not surprising that many businesses know the importance of having their own business blog. You can even find accounting blog or other niche blog that is of your interest. Even if you do a search online, the first few results would normally indicated that the information you are looking for are posted in various blogs. So, if you something to share to everybody, start a blog.